WO2019080001A1 - Nanoscale diamond needle structure, preparation method therefor and application thereof - Google Patents

Abstract

The present invention relates to a nanoscale diamond needle structure which comprises a diamond base layer (1) and a plurality of nanoscale diamond needles (2) extending over a surface of the diamond base layer (1), adjacent nanoscale diamond needles (2) being spaced apart from each other, and a colored core structure (3) being further distributed in the surface layer of diamond needle at the nanoscale. The present invention also relates to a method of preparing the nanoscale diamond needle structure and an application of the nanoneedle structure to prepare a device for delivering a material into cells.

Description

 Diamond nanoneedle structure and preparation method and application thereof

 [0001] The present invention belongs to the field of biomaterials, and particularly relates to a diamond nanoneedle structure and a preparation method and application thereof.

 Background technique

 [0002] Diamond materials are based on excellent physical, chemical properties and biocompatibility, as well as the fluorescence properties of nanodiamonds and the modification of surface groups, which have led to widespread interest in the application of nanostructured diamond materials in biomedical applications. . As an excellent biocompatible material, the color center such as nitrogen-vacancy (NV) in diamond is a composite structure composed of a substitutional nitrogen atom (N) in diamond and a carbon vacancy (V) in the ortho position. Ultra-high light stability and thermal stability, its fluorescence is not affected by size and surface modification. However, NV color centers are extremely sensitive to physical quantities such as magnetic fields, temperature, stress, and electric fields, and have long coherence and relaxation at room temperature, and are therefore often used for high sensitivity measurements of these physical quantity parameters. Based on these advantages, diamond NV nanomaterials are ideal fluorescent probes for fluorescent labeling, 3D tracking, bioimaging, and biosensing of cells. However, the preparation of high-quality NV color centers exists only in diamond nanoparticles and high-quality single crystal diamond sheets, which greatly limits the range of applications.

[0003] In addition to nano-sized diamond particles, recently vertically aligned diamond nanoneedle arrays have been used for efficient intracellular transport and detection. Compared to chemical and biological methods to achieve this goal, diamond nanoneedles show significant advantages in cell transport, with versatility, simple operation, high efficiency, low cost and safety, enabling controlled transfer of materials to a specific organ within a cell. Mechanical piercing of cell membranes with high aspect ratio nanomaterials has become a promising means of delivering substances to cells and enabling intracellular detection. Studies have shown that silicon nanowires or silicon nanoneedle arrays can be used to achieve intracellular neural network detection and intracellular drug delivery applications. Compared to silicon nanomaterials, diamond nanowire structures retain very high Young's modulus, yield strength and rupture strength. At present, a device for transferring a substance into a cell using a diamond nanoneedle array is disclosed, and the biomolecule which needs to enter the cell can be directly and easily transmitted through the cell membrane by the method. Chemotherapy drugs, antibodies, and other biomolecules can be delivered directly into the cytoplasm without the need to pass signaling pathways through traditional cells. Using this method can Successfully transfected with nerve cells, the transfection efficiency is as high as 45%, only 10 minutes, but the current commercial method of transfection is generally less than 5%, which requires a small number of defects. In another document, the same purpose can be achieved by using nano-needles of materials such as diamond, cubic boron nitride, carbon nitride, boron nitride, boron boron nitride, and metal boride. However, the application of diamond nanoneedle arrays in these work is currently based on the excellent mechanical properties of diamonds and the ease of modification of the surface. The diamond nanoneedle itself does not emit fluorescence, and it is necessary to modify the fluorescent protein as a marker on its surface. The operation process is cumbersome, and the selectivity and detection sensitivity of the biological probe molecular modification on the surface of the diamond nanoneedle can have a serious impact.

[0004] Zero-dimensional diamond nanoparticles and one-dimensional diamond nanostructures have shown increasing use in drug delivery, bioimaging, and biosensing. The application of zero-dimensional diamond nanoparticles mainly utilizes the special fluorescent light-emitting characteristics such as NV color center, and the one-dimensional diamond vertical nanoneedle array structure mainly utilizes the excellent mechanical properties of diamond to pierce the cell membrane to realize intracellular transmission and detection. Therefore, it is of great scientific significance to study the biosensing of intracellular cells with diamond nanomaterials such as NV color center and vertical array nanoneedle array structure, such as studying changes in intracellular temperature, magnetic field and electrophysiological properties. And application value. At present, although attempts have been made to integrate, for example, NV color centers in one-dimensional diamond nanostructures, the formation rate such as NV color center is low, and the depth distribution is very dispersed, that is, high quality color centers cannot be formed.

 technical problem

 [0005] The object of the present invention is to overcome the above-mentioned deficiencies of the prior art, to provide a diamond nanoneedle structure, a preparation method thereof and an application thereof, so as to solve the problem that the existing diamond nanoneedle cannot integrate the high quality color core of the diamond, resulting in failure to Technical problems of excellent fluorescence luminescence properties and electron spin coherence properties.

 Problem solution

 Technical solution

 In order to achieve the above object of the invention, in one aspect of the invention, a diamond nanoneedle structure is provided. The diamond nanoneedle structure comprises a diamond base layer and a plurality of diamond nanoneedles extending on a surface of the diamond base layer, adjacent to the diamond nanoneedles being spaced apart from each other, and a color center structure is also distributed in the diamond nanoneedle surface layer .

 In another aspect of the invention, a method of making a diamond nanoneedle structure is provided. The method for preparing the diamond nanoneedle structure comprises the following steps:

[0008] etching a diamond film layer, etching to form a plurality of diamond nanoneedles, the diamond nanoneedle Interval with each other;

 [0009] sequentially growing a first pure diamond layer, a delta-dense layer, and a second pure diamond layer on the surface of the diamond nanoneedle;

 [0010] The diamond nanoneedles grown with the delta-taste layer are subjected to electron beam irradiation treatment and then annealed in a protective atmosphere.

[0011] In another aspect of the invention, a method of applying the above-described diamond nanoneedle structure is provided. The use of the claimed diamond nanoneedle structure in a fluorescent luminescent probe, biosensing, and device for delivering a substance to a cell.

 Advantageous effects of the invention

 Beneficial effect

 [0012] Compared with the prior art, the above-mentioned diamond nanoneedle structure has a color center structure distributed on the surface layer of the diamond nanoneedle, thereby imparting excellent mechanical properties to the diamond nanoneedle structure of the present invention, and also having excellent performance. Fluorescence properties and electron spin coherence properties. Moreover, the color center structure is distributed in the shallow layer of the diamond nanoneedle, thereby making the color center structure uniform and imparting excellent fluorescence and sensing properties to the diamond nanoneedle structure of the present invention.

 [0013] The above method for preparing a diamond nanoneedle structure is to prepare a shallow color center structure by sequentially growing a sandwich layer delta-grained diamond layer of a diamond layer/de lta-grain layer/diamond layer on a diamond nanoneedle surface layer, thereby realizing effective control of diamond The generation and distribution of the color center structure in the surface layer ensures the intensity, stability and sensitivity of the color center structure fluorescence emission. Thus, the prepared diamond nanoneedle structure not only has the mechanical properties of the diamond nanoneedle, but also has excellent fluorescence luminescent properties and electron spin coherence characteristics. In addition, the steps of the preparation method of the invention can be effectively controlled, thereby ensuring the stable performance of the prepared diamond nanoneedle structure, high efficiency, and industrial production.

[0014] Since the diamond nanoneedle structure further has a color center structure distributed in the surface layer of the diamond nanoneedle, the diamond nanoneedle structure can not only penetrate the cell membrane to realize the transmission and detection of the intracellular substance, but also can realize Biomedical applications such as biosensing and bioimaging are more widely used, especially to detect the response of nerve cells to external stimuli and intracellular activities, and to promote the diagnosis, treatment and rehabilitation of neurological diseases. research Development.

 Brief description of the drawing

DRAWINGS 1 is a schematic view showing a process flow of a method for preparing a diamond nanoneedle structure according to an embodiment of the present invention;

 2 is a sandwich structure of a pure diamond layer/delta-dense layer/pure diamond layer sequentially grown on the surface of a diamond nanoneedle during the preparation of a diamond nanoneedle structure;

Figure 3 is an enlarged view of a portion shown in A of Figure 2;

4 is a schematic view showing the structure of a diamond nanoneedle according to an embodiment of the present invention.

Embodiments of the invention

 [0019] In order to make the technical problems, technical solutions, and advantageous effects to be solved by the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

 [0020] In one aspect, an embodiment of the present invention provides a diamond nanoneedle structure having a color center structure. The diamond nanoneedle structure is as shown in Fig. 4, which comprises a diamond substrate layer 1 and a plurality of diamond nanoneedles 2 extending on the surface of the diamond substrate layer 1.

 [0021] wherein the diamond matrix layer 1 contained in the diamond nanoneedle structure has at least a bonded surface. In one embodiment, the diamond matrix layer 1 is an electron-grade purity diamond flake or a preferentially oriented polycrystalline diamond thick film. The use of this type of diamond matrix layer can effectively ensure the formation of diamond nanoneedles 2, such as etching, avoiding the complicated processes of cutting, etching thinning, polishing, etc., and very limited size (usually 3). -5 mm) , which satisfies the need of etching diamond nanoneedle 2 for intracellular material transport and detection. The diamond nanoneedle 2 obtained by the same method is a single crystal structure, and there are very few impurities and defects inside, which do not affect diamond. Fluorescence luminescence and spin coherence properties of the center of the color center contained in the surface layer of the nanoneedle 2.

 [0022] The diamond nanoneedle 2 contained in the diamond nanoneedle structure extends from the surface of the diamond base layer, specifically, from the surface of the diamond base layer 1 and along a direction away from the surface of the diamond base layer 1, that is, That is, the diamond nanoneedle 2 is at an angle to the surface of the diamond substrate layer 1, and the angle of the angle may be a conventional range, such as 60 ° to 90 °, preferably 90 ° in the embodiment of the present invention. .

[0023] In addition, the diamond nanoneedles 2 are spaced apart on the surface of the diamond matrix layer 1, that is, the two adjacent diamond nanoneedles 2 are spaced apart from each other, as in an embodiment, The diamond nanoneedles 2 constitute a diamond nanoneedle array. In a specific embodiment, the diamond nanoneedles 2 are distributed The diamond substrate layer 1 has a density of 10 4 - 10 9 needles / _cm 2 . By controlling the distribution density of the diamond nanoneedles 2, it is possible to control the fluorescence and sensing performance and efficiency of the above-described diamond nanoneedle structure, such as processing a large number of cells at a time, improving the efficiency of delivering substances and the efficiency of monitoring a large number of cells at one time.

 [0024] In one embodiment, the diamond nanoneedle 2 has a diameter of 100-2000 nm and a height of 2-10 μm. In another embodiment, the diamond nanoneedle 2 has a aspect ratio of 10-70. Wherein, the diameter of the diamond nanoneedle 2 refers to the diameter of the trunk portion of the diamond nanoneedle 2.

 [0025] On the basis of the above embodiments, the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 2, that is, the color center structure 3 is distributed in the shallow layer on the surface of the diamond nanoneedle 2. In one embodiment, the density of the core structure 3 in the surface layer of the diamond nanoneedle 2 is 1-5000 per needle, preferably 500-5000 per needle. Among them, when the color center structure 3 is concentrated on the tip end portion of the diamond nanoneedle 2, it may have a small amount of distribution. In another embodiment, the distance of the core structure 3 from the surface of the diamond nanoneedle 2 is less than or equal to 100 nm. Wherein, the distance should be understood as the distance from the geometric midpoint to a face, specifically the distance from the color center structure 3 to the surface of the diamond nanoneedle 2. In a specific embodiment, the color center structure 3 is a color center structure formed by at least one of N, Si, P, and B, specifically, such as an NV color center structure.

 [0026] Thus, the diamond nanoneedle 2 contained in the diamond nanoneedle structure in each of the above embodiments has not only a high aspect ratio, but also less impurities and defects, high purity, and preferably a single crystal structure, and has excellent mechanical properties; In this same way, the color center structure 3 distributed in the shallow layer of the diamond nanoneedle 2 is uniform, and has excellent fluorescence luminescent properties and electron spin coherence characteristics. Moreover, it is possible to process a large number of cells at a time, to deliver high material efficiency and to perform monitoring of a large number of cells. Therefore, the above-described diamond nanoneedle structure has excellent fluorescence and sensing properties and high efficiency in processing cells on the basis of excellent mechanical properties.

 [0027] In another aspect, embodiments of the present invention also provide a method of fabricating the diamond nanoneedle structure described above. The process of preparing the diamond nanoneedle structure described above is as shown in FIG. 1, combined with the diamond nanoneedle structure shown in FIG. 2-4, and the preparation method thereof comprises the following steps:

 [0028] Step S01. The diamond film layer is etched to form a diamond nanoneedle: etching the diamond film layer, etching to form a plurality of diamond nanoneedles 2;

 [0029] Step S02. growing a delta-difficult layer on the surface of the diamond nanoneedle: sequentially growing a first pure diamond layer 31, a delta-difficult layer 32 and a second pure diamond layer 33 on the surface of the diamond nanoneedle 2;

[0030] Step S03. Electron beam irradiation and annealing treatment on the delta-difficult layer: the delta-miscible growth will be grown The diamond nanoneedles of the layer are subjected to electron beam irradiation treatment to produce vacancies required to form a color center, and then annealed in a protective atmosphere.

 [0031] Specifically, in the above step S01, the diamond film layer is used for etching to form the diamond nanoneedles 2.

a portion of the defect portion is etched away by etching, thereby forming a plurality of diamond nanoneedles 2 on the etched surface of the diamond film layer, and the unetched remaining diamond film layer is configured to carry the Diamond nanoneedle 2 of diamond nanolayer 2 as described in Figures 2 and 4. The etching process should be such that the formed diamond nanoneedles 2 are spaced apart from each other, and the sides of the diamond nanoneedles 2 are perpendicular to the surface of the diamond substrate layer. The method of etching to form the diamond nanoneedles 2 may be a conventional etching method. In an embodiment, the etching method uses an ECR-assisted microwave plasma etching or an ICP etching device to perform a nano-etching structure on the surface of the diamond film layer, wherein the etching gas may be but not only hydrogen gas. At least one of argon, oxygen, CF ₄ , SF _{6 ,} etc., and other common etching gases. The reactive ion etching process is a process of physical etching and chemical etching, and needs to be balanced by the adjustment of the process conditions. The lower pressure in the ECR plasma can obtain diamond nanometers with higher aspect ratio. The needle, when the addition of Ar gas and the enhancement of microwave power make the sidewalls more vertical. The nanodiamonds and defects at the grain boundaries are first etched away, resulting in a diamond nanoneedle 2.

 [0032] In an embodiment, when the diamond nanoneedle 2 吋 is formed by an ECR-assisted microwave plasma etching method, the conditions of the ECR-assisted microwave plasma etching are:

[0033] Total gas flow rate: 10-50 sccm, Ar gas 0-50<3⁄4, H ₂ gas 50-100%, Air pressure: (5-8) xl0 ³ mTorr, Microwave power: 700-1000 W, Substrate plus DC The negative bias voltage is -190~-230V, the etching time is 2-6 hours, and the magnetic field strength of the ECR area is 875 Gauss;

 [0034] In a specific embodiment, the conditions of the ECR-assisted microwave plasma etching are: the etching gas is hydrogen/argon gas, and the hydrogen/argon gas flow rate is: 11 sccm/9 sccm, total gas flow rate: 20 sccm; : (5-8)xl0 3 mTorr, microwave power: 700-1000W, substrate plus DC negative bias -190~- 230V, 2-6 吋 between etched turns, 875 Gauss in ECR .

 [0035] In another embodiment, when the diamond nanoneedle 2 is formed by ICP etching, the ICP etching conditions are as follows:

[0036] using one or more of hydrogen, argon, oxygen, helium, nitrogen, a gaseous carbon source, CF ₄ , C ₄ F ^SF ₆ as a reaction gas, the flow rate of the reaction gas is 5 to 200 sccm, the reaction Air pressure is 0.1~10Pa, etc. The power supply of the ion body is 500~3000W, the RF power on the substrate stage is 50~300W, and the etching time is 10~600 min.

[0037] By controlling the parameters of the ECR-assisted microwave plasma etching or ICP etching, the diamond nanoneedle 2 formed by etching has a higher aspect ratio, such as etching formed in the diamond nanoneedle structure as described above. The diamond nanoneedle 2 is preferably such that the sidewall of the diamond nanoneedle 2 formed by etching is perpendicular to the surface of the diamond substrate layer 1. In addition, during the plasma etching process, molybdenum and molybdenum carbide particles are spontaneously formed on the surface of the diamond film layer due to the bombardment and sputtering of the surface of the molybdenum substrate on the surface of the etched diamond film layer. The mask of the eclipse. According to previous research work, electrons are emitted in the process of etching such as RIE, ECR, ICP, etc. due to the presence of more sp ² phases and defects at the boundary of the diamond negative electron affinity and columnar structure. Stronger, the generated electric field is unevenly distributed, and the diamond at the grain boundary and the spontaneously formed mask are preferentially etched. By optimizing the reaction conditions of the etching process, a diamond nanometer needle with high quality single crystal structure is obtained. 2, and ensure that the diamond nanoneedle 2 has a high aspect ratio, and the sidewalls are vertical and smooth.

[0038] In the step S01, the etched diamond film layer may be a conventional diamond film. For an embodiment of the present invention, an electronic grade purity diamond flake or a preferential orientation polycrystalline diamond thick film is selected as an embodiment. The etched diamond film layer avoids the complicated process of cutting, etching thinning, polishing, etc., and very limited size (usually 3-5 mm), which is used for CVD single crystal diamond, and is suitable for diamond nanoneedle 2 The need for intracellular material transport and detection, the diamond nanoneedle 2 obtained by the same method is a single crystal structure, the sidewall is smooth, and there are very few impurities and defects existing inside, which does not affect the fluorescence luminescence and spin coherence characteristics of the NV center.

[0039] In an embodiment, the preferentially oriented polycrystalline diamond thick film may be prepared as follows: [0040] prepared by microwave plasma chemical vapor deposition (MPCVD) or hot filament chemical vapor deposition (HFCVD), film The bias assisted nucleation is first performed in the pre-growth stage. Taking HFCVD as an example, double-biased hot wire chemical vapor deposition is used. During nucleation, a positive bias is applied to the gate above the hot wire, and a negative bias is applied to the substrate. For microwave plasma CVD, a negative bias is applied to the substrate. During the nucleation process, the proportion of methane is slightly higher. After about half an hour, the nucleation process is completed, the bias power supply is turned off, and the methane concentration and other process parameters are adjusted to the conditions suitable for the growth of the preferred oriented diamond film. The [001] oriented diamond film is first selectively grown such that the grown diamond seed has a higher <001> orientation of the vertical substrate, and then the process parameters are adjusted such that {001} The surface is expanded to obtain a (001) preferred oriented diamond film.

In a specific embodiment, the above preferred orientation polycrystalline diamond thick film preparation can be prepared by the method of the step S11 in the following Example 1.

 [0042] In the above step S02, when the surface of the diamond nanoneedle 2 formed by etching in the above step S01 is sequentially followed by the first pure diamond layer 31, the delta-dense layer 32 and the second pure diamond layer 33, then in the diamond nano The sandwich structure of the pure corundum layer/delta-dense layer/pure diamond layer is grown on the surface of the needle 2, as shown in Figs. 2 and 3.

 [0043] wherein, the first pure diamond layer 31 and the second pure diamond layer 33 may be grown by a method capable of growing pure diamond, and the method of growing the delta-difficult layer 32 may also adopt a method capable of growing a delta-discrete layer. In one embodiment, the first pure diamond layer 31, the delta-taste layer 32, and the second pure diamond layer 33 are formed by CVD deposition, specifically but not exclusively by microwave plasma chemical vapor deposition.

 [0044] In one embodiment, the condition of growing the first pure diamond layer 31 on the surface of the diamond nanoneedle 2 by using a microwave plasma chemical vapor deposition method and/or growing the second pure diamond layer 33 on the surface of the delta-taste layer 32 is :

[0045] The base vacuum is >10 - ⁶ Pa, and the substrate temperature is 600 to 900. C, total flow rate of diamond carbon source gas/hydrogen gas mixture: 200~2000 sccm, wherein the volume percentage of diamond carbon source gas is 0.01~0.5<3⁄4, hydrogen volume percentage is 99.5 99.9%, gas pressure: 20-40 Torr, microwave power: 500-1200W, 2-20 hours after deposition.

 In a specific embodiment, the conditions for growing the first pure diamond layer 31 and/or growing the second pure diamond layer 33 by microwave plasma chemical vapor deposition are:

[0047] The base vacuum is >10 - ⁶ Pa, and the substrate temperature is 800. C, diamond carbon source gas / hydrogen flow ratio: 0.1

 Sccm/400sccm, total gas flow: 400 sccm, air pressure: 30 Torr, microwave power: 1200W, 10 hours after deposition.

[0048] In the above method for growing the first pure diamond layer 31 and the second pure diamond layer 33 by microwave plasma chemical vapor deposition, in one embodiment, the diamond carbon source gas is methane, acetylene, acetone, ethanol At least one of them. Wherein the methane is a ¹² CH ₄ isotope gas. I2CH ₄ using isotope gas can be effectively reduced spin 1/2 of I3C, and ¹² C is zero spin, and therefore can not be detected ¹² C nuclear magnetic resonance and the like. For the ¹² C isotope-purified diamond, the coherent diurnal and dephasing phases of the color center are very long. ¹² C purified diamond is used in some applications that utilize the spin coherence of the NV center to improve the fluorescence intensity and detection sensitivity of the diamond nanoneedle in biosensing. [0049] In another embodiment, the conditions for the delta-grain layer 32 on the surface of the first pure diamond layer 31 by microwave plasma chemical vapor deposition are:

[0050] The base vacuum is >10 - ⁶ Pa, and the substrate temperature is 600 to 900. C, total flow of mixed gas of diamond carbon source gas/hydrogen/chaotic elemental gas: 200~2000

 Sccm, the volume percentage of the diamond carbon source gas is 0.01 to 0.5%, the volume percentage of the hydrogen is 80 to 9 9%, and the mass ratio of the impurity element to the carbon element is 1 to 20<3⁄4 (1000-10000).

 Ppm), air pressure: 20-40 Torr, microwave power: 500-1200W, deposition time 5~20 minutes;

[0051] In a specific embodiment, the conditions for the delta-discrete layer 32 by microwave plasma chemical vapor deposition are:

 [0052] The substrate temperature is 800. C, diamond carbon source gas / hydrogen / miscellaneous element gas mixed gas total flow rate: 0.1 sccm / 390 sccm / 10 sccm, total gas flow: 400 sccm, gas pressure: 30 Torr, microwave power: 1200W.

In the above method for growing the delta-grain layer 32 by microwave plasma chemical vapor deposition, in one embodiment, the diamond carbon source gas is at least one of methane, acetylene, acetone, and ethanol. Wherein the methane is a ¹² CH ₄ isotope gas.

[0054] In another embodiment, the miscellaneous element used in the method of growing the delta-taste layer 32 is at least one of N, Si, P, B. In a particular embodiment, N can be N ₂ , specifically ¹⁵ N ₂ . The use of ¹⁵ N is sufficient to avoid the effects of nitrogen-vacancy defects inherent in the diamond nanoneedle 2. Si may be provided as a gaseous compound of Si such as silane (SiH ₄ ), trimethylsilane (TMS), tetraethyl orthosilicate, and the like. P may be provided as a gaseous compound of P, such as phosphine (PH ₃ ), trimethylphosphane (TMP), trimethyl phosphate, and the like. B may be provided as a gaseous compound of B, such as diborane (B ₂ H ₆ ), trimethylborane (TMB), trimethyl borate, etc.

[0055] The first pure diamond layer 31, the delta-dummy layer 32, and the second pure diamond layer 33 are controlled by the conditions of growing the first pure diamond layer 31, the delta-taste layer 32, and the second pure diamond layer 33. The growth rate is preferably a slow growth rate (as in the specific embodiment described above, a growth rate of about 10 nm/h), an epitaxial mass and thickness, and a delta-difficult layer 32. Therefore, it is ensured that the generated color center structure 3 is evenly distributed in the shallow layer of the diamond nanoneedle 2 after being processed by the above step S03. The density and depth of the color center structure 3 can be controlled by controlling the density of the color center structure 3 in the shallow layer of the diamond nanoneedle 2. The density and depth of the color center structure 3 as described in the diamond nanoneedle structure above. In addition, the growth thickness of each layer can be calibrated using a secondary ion mass spectrometer (SIMS), and the impurity concentration of the delta-taste layer 32 can be measured.

 [0056] In the above step S03, the diamond nanoneedle 2 having the delta-taste layer grown on the surface in step S02 is subjected to electron beam irradiation treatment and annealing treatment, and then formed in the shallow layer of the diamond nanoneedle 2 surface layer. Colored core structure 3. Wherein, after the electron beam irradiation treatment, the vacancies required to form the color center structure 3 are generated in the delta-difficult layer. Annealing results in a color center structure 3 in the delta-taste layer.

[0057] In an embodiment, in step S03, the diamond nanoneedle 2 表面 having a delta-grain layer grown on the surface is treated by electron beam irradiation, and the condition of the electron beam irradiation treatment is: the irradiation energy is 2-4 MeV, The dose is (1-9) x 10 ¹⁴ cm 2 ; as in the specific embodiment, the conditions of the electron beam irradiation treatment are: irradiation energy of 2 MeV and dose of 10 14 cm -2 . The vacancies required to form the color center are generated by high-energy electron beam irradiation, thereby increasing the generation rate of the color center structure 3.

 [0058] In another embodiment, the annealing treatment has a temperature of 800. Above C, the daytime is 2-4 hours. As a specific example, the annealing treatment temperature is 850. C, the day is 2 hours. Under this condition, it is effective to ensure that the color center structure 3 is formed in the shallow layer of the diamond nanoneedle 2.

 In addition, the protective atmosphere in the annealing treatment may be an argon protective atmosphere or a vacuum protective atmosphere to ensure the formation of the color center structure 3 in the annealing treatment.

 In a further embodiment, after the annealing treatment in step S03, further comprising the step of subjecting the annealed diamond nanoneedle to oxidation treatment in an acid solution. Since the surface termination has a great influence on the luminescence characteristics of the color center structure 3, the oxygen termination of the surface negative potential is obtained by the oxidation treatment, and the luminescence stability of the color center structure 3 is ensured. Further, the photodetection magnetic resonance spectrum can be used to measure the coherence between the coherent turns and the electric field of the color center structure 3 obtained by the above-described preparation method.

[0061] In a specific embodiment, the oxidation treatment after the annealing treatment in the step S03 is performed by placing the annealed diamond nanoneedle in a mixed acid solution to be heated to 200. C, maintained for more than 30 minutes, wherein the mixed acid solution comprises a mixed acid of H ₂ S0 ₄ , HN 0 ₃ and 1100 _{4 in} a volume ratio of 1: (1-3): (1-3). By using the mixed acid solution and the temperature and the oxidation treatment between the crucibles, the oxygen terminal of the negative potential of the surface of the diamond nanoneedle 2 is effectively obtained, and the luminescent stability of the color center structure 3 is provided.

[0062] Therefore, the above method for preparing a diamond nanoneedle structure sequentially grows gold in the surface layer of the diamond nanoneedle 2 The layered delta-tough diamond layer of the corrugated layer/delta-difficult layer/diamond layer is used to prepare the shallow color center structure 3, thereby effectively controlling the generation and distribution of the color center structure 3 in the diamond surface layer, thereby ensuring the color center structure 3 The intensity, stability and sensitivity of fluorescent light. The prepared diamond nanoneedle structure not only has the mechanical properties of the diamond nanoneedle 2, but also has excellent fluorescence luminescence properties and electron spin coherence characteristics. In addition, each step of the above preparation method can be effectively controlled, thereby ensuring stable performance of the prepared diamond nanoneedle structure, high efficiency, and industrial production.

In still another aspect, in addition to the above-described diamond nanoneedle structure and method of preparing the same, embodiments of the present invention also provide an apparatus for delivering a substance to a cell. The device can include conventionally necessary components, such as diamond nanoneedle structural components, that deliver the device to the cells. However, the diamond nanoneedle structural member is the diamond nanoneedle structure of the embodiment of the present invention as shown in Fig. 4 described above or the diamond nanoneedle structure prepared by the above-described diamond nanoneedle structure preparation method. Thus, as described above, the diamond nanoneedle 2 contained in the diamond nanoneedle structure described above has a high aspect ratio with few impurities and defects, and is preferably a single crystal structure so that the surface thereof is smooth, Excellent mechanical properties; at the same time, the color center structure 3 distributed in the shallow layer of the diamond nanoneedle 2 is uniform, and has excellent fluorescence luminescence properties and electron spin coherence characteristics. Therefore, the above-mentioned diamond nanoneedle structure has excellent fluorescence and sensing properties on the basis of excellent mechanical properties. Thus, the above device for intracellular delivery of a substance containing the diamond nanoneedle structure of the embodiment of the present invention as described above in FIG. 4 can not only penetrate the cell membrane to realize the transport and detection of intracellular substances, but also achieve It has a wider range of applications in the biomedical fields such as biosensing and bioimaging, especially to detect the response of nerve cells to external stimuli and intracellular activities, and to promote the diagnosis, treatment and rehabilitation of nervous system diseases. Research development.

 [0064] The diamond nanoneedle structure and the preparation method thereof according to the embodiment of the present invention will be further described in detail in conjunction with specific examples.

Embodiment 1

[0066] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1. [0067] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0068] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0069] A 5-10 micron thick diamond film layer was prepared on a l-5 cmxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface, and then the silicon wafer was ultrasonically cleaned for 10 minutes in an acetone solution, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution. Minutes; the cleaned silicon substrate is placed on a molybdenum substrate and placed in a C VD device, evacuated to a temperature below 10 - ⁵ Pa; a residual oxide layer on the surface of the wafer with hydrogen plasma before film growth Wash again with other impurities: Air pressure: 30 Torr, Microwave power: 1200 W, Silicon substrate temperature: 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, nucleation: 12 minutes. The specific parameters for (001) preferred orientation diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 10 hours;

 [0070] S12. etching the diamond film layer to form a diamond nanoneedle array 2:

[0071] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, the substrate temperature is lowered to room temperature, the vacuum is evacuated to 10 5 Pa, and then the hydrogen is recharged to 7 mTorr, and the ECR microwave plasma mode is applied, and the electromagnetic is applied. The magnetic field provided by the coil has an intensity of 875 Gauss in the ECR zone. The specific parameters of reactive ion etching in the ECR-assisted microwave plasma are as follows: Hydrogen/argon flow: 11 sccm/9 sccm, total gas flow: 20 sccm, air pressure: 7xlO - ³ mTorr, microwave power: 800W, substrate plus DC negative bias -200V, 2 turns after etching; after biasing, turn off bias voltage, microwave power, electromagnetic coil power, turn off gas, get Single crystal diamond nanoneedle array 2;

 [0072] S13. Growing a delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0073] After the completion of the reactive ion etching to prepare the diamond nanoneedle array 2, the delta-disintegrating diamond layer is continuously grown in the microwave plasma CVD mode; firstly, a high-purity epitaxial diamond is grown on the surface of the diamond nanoneedle array 2. Layer 31, ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process. In order to obtain higher epitaxial quality, very slow growth conditions are used, and the growth rate is about 10 nm/h. The specific process conditions are as follows: Basic vacuum >10 - ⁶ ? &, substrate temperature 800. C, A hospital / hydrogen gas flow ratio : 0.1 sccm/400 sccm, total gas flow 400 sccm, pressure 30 Torr, microwave power 1200 W, deposition of 5 吋 between turns; then growth of nitrogen miscellaneous layer 32 on the surface of high-purity epitaxial diamond layer 31, using 15N ₂ isotope gas (Purity > 98%) The process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / nitrogen flow: 0.1 sccm / 390 sccm / 10 sccm, total gas flow: 400 sccm, pressure: 30 Torr, microwave power: 1200W, deposition 0.5 吋 between the day; finally a high-purity epitaxy The diamond layer 33 is grown under the following conditions: substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, deposition 5 吋 between turns; final growth diamond layer 31/nitrogen miscellaneous layer 32/ The structure of the diamond layer 33 is as shown in Figures 2 and 3;

[0074] S14. Post-treatment to obtain a shallow NV center 3 diamond nanoneedle:

[0075] The diamond nanoneedle array 2 grown with the delta miscellaneous diamond layer in step S14 is irradiated by high energy electron beam to generate the vacancies required to form the NV color center 3, the irradiation energy is 2 MeV, and the dose is 10" cm -2 Subsequently, the NV color center is generated by high-temperature vacuum annealing, and the temperature of the vacuum annealing furnace is maintained at 850 ° C for two hours, and the diamond nanoneedle array is placed in a volume ratio of 1: 1: 1 H ₂ SO ₄ : HNO ₃ : HC10 ₄ Heat in medium to boil to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with an oxygen terminal on the surface to ensure the stability of the negative potential of the NV color center.

 Example 2

 [0077] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1.

 [0078] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0079] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0080] A 5-10 micron thick diamond film layer was prepared on a l-5 cmxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface, and then the silicon wafer was ultrasonically cleaned for 10 minutes in an acetone solution, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution. Minutes; the cleaned silicon substrate is placed on a molybdenum substrate and placed in a C VD device, evacuated to a temperature below 10 - ⁵ Pa; a residual oxide layer on the surface of the wafer with hydrogen plasma before film growth Wash again with other impurities: Air pressure: 30 Torr, Microwave power: 1200 W, Silicon substrate temperature : 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, nucleation: 12 minutes. The specific parameters for (001) preferred orientation diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 20 hours;

[0081] S12. Etching the diamond film layer to form a diamond nanoneedle array 2:

[0082] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, the substrate temperature is lowered to room temperature, the vacuum is evacuated to 10 ⁵ Pa, and then the hydrogen is recharged to 7 mTorr, and the ECR microwave plasma mode is applied, and the electromagnetic is applied. The magnetic field provided by the coil has an intensity of 875 Gauss in the ECR zone. The specific parameters of reactive ion etching in the ECR-assisted microwave plasma are as follows: Hydrogen/argon flow: 11 sccm/9 sccm, total gas flow: 20 sccm, air pressure: 7xlO - ³ mTorr, microwave power: 800W, substrate plus DC negative bias -230V, etched dip is 4 hours; after the etching is completed, turn off the bias voltage, microwave power, electromagnetic coil power, turn off the gas, get Single crystal diamond nanoneedle array 2;

 [0083] S13. Growing a delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0084] After the completion of the reactive ion etching to prepare the diamond nanoneedle array 2, the delta-disintegrating diamond layer is continuously grown in the microwave plasma CVD mode; firstly, a high-purity epitaxial diamond is grown on the surface of the diamond nanoneedle array 2. Layer 31, ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process. In order to obtain higher epitaxial quality, very slow growth conditions are used, and the growth rate is about 10 nm/h. The specific process conditions are as follows: Basic vacuum >10 -6 ? &, substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, deposition 10 吋 between turns; then growth of nitrogen on the surface of high-purity epitaxial diamond layer 31 The impurity layer 32, using i5N ₂ isotope gas (purity > 98%), the process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / nitrogen flow: 0.1 sccm / 390 sccm / 10 sccm, total gas flow: 400 sccm, pressure: 30 Torr, microwave power: 1200W, deposition 0.5 吋 between the day; finally a high-purity epitaxy The diamond layer 3 3 is grown under the following conditions: substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, 10 吋 between depositions; final growth diamond layer 31/nitrogen miscellaneous layer 32/ The structure of the diamond layer 33 is as shown in Figures 2 and 3; [0085] S14. Post-treatment to obtain a diamond N-center of the shallow NV center 3:

[0086] The diamond nanoneedle array 2 grown with the delta miscellaneous diamond layer in step S14 is subjected to high energy electron beam irradiation to generate the vacancies required to form the NV color center 3, the irradiation energy is 2 MeV, and the dose is 10" cm -2 Subsequently, the NV color center is generated by high-temperature vacuum annealing, and the temperature of the vacuum annealing furnace is maintained at 850 ° C for two hours, and the diamond nanoneedle array is placed in a volume ratio of 1:1:1 H ₂ SO ₄ :HNO ₃ :HC10 ₄ Heat in medium to boil to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with an oxygen terminal on the surface to ensure the stability of the negative potential of the NV color center.

 Example 3

 [0088] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1.

 [0089] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0090] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0091] A 5-10 micron thick diamond film layer was prepared on a l-5 _C mxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface, and then the silicon wafer was ultrasonically cleaned for 10 minutes in an acetone solution, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution. Minutes; the cleaned silicon substrate is placed on a molybdenum substrate, placed in a C VD device, and evacuated to a temperature below 10 -5 p _a ; residual oxidation of the silicon surface by hydrogen plasma before film growth The layer and other impurities are washed again: Air pressure: 30 Torr, Microwave power: 1200 W, Silicon substrate temperature: 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, nucleation: 12 minutes. The specific parameters for (001) preferred orientation diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 20 hours;

 [0092] S12. Etching the diamond film layer to form a diamond nanoneedle array 2:

[0093] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, and the substrate temperature is lowered to room temperature, and the vacuum is applied to 10 5 Pa, then recharge the hydrogen to 7 mTorr, the ECR microwave plasma mode is applied, and the magnetic field provided by the electromagnetic coil is 875 Gauss in the ECR region, and the specific parameters of the reactive ion etching in the ECR assisted microwave plasma are performed. As follows: Hydrogen / argon flow: 11 sccm / 9 sccm, total gas flow: 20 sccm, pressure: 7xlO - ³ mTorr, microwave power: 800W, substrate plus DC negative bias -230V, etched time is 4 After the etching is completed, the bias voltage, the microwave power supply, the electromagnetic coil power supply, the gas is turned off, and the single crystal diamond nanoneedle array 2 is obtained;

[0094] S13. Growing a delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0095] After the completion of the reactive ion etching to prepare the diamond nanoneedle array 2, the delta-disintegrating diamond layer is continuously grown in the microwave plasma CVD mode; firstly, a high-purity epitaxial diamond is grown on the surface of the diamond nanoneedle array 2. Layer 31, ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process. In order to obtain higher epitaxial quality, very slow growth conditions are used, and the growth rate is about 10 nm/h. The specific process conditions are as follows: Basic vacuum >10 -6 ? &, substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, deposition of 5 吋 between turns; then growth of nitrogen on the surface of high-purity epitaxial diamond layer 31 The impurity layer 32, using 15N ₂ isotope gas (purity > 98%), the process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / nitrogen flow: 0.1 sccm / 300 sccm / 100 sccm, total gas flow: 400 sccm, pressure: 30 Torr, microwave power: 1200W, 1 hour after deposition; finally a high-purity epitaxy The diamond layer 33 is grown under the following conditions: substrate temperature 800. C, A hospital / hydrogen gas flow ratio: 0.1 sccm / 400 sccm, total gas flow 400 sccm, pressure 30 Torr, microwave power 1200 W, deposition time 20 hours; final growth diamond layer 31 / nitrogen miscellaneous layer 32 / The structure of the diamond layer 33 is as shown in Figures 2 and 3;

 [0096] S14. Post-treatment to obtain a shallow NV center 3 diamond nanoneedle:

[0097] The diamond nanoneedle array 2 grown with the delta miscellaneous diamond layer in step S14 is subjected to high energy electron beam irradiation to generate the vacancies required to form the NV color center 3, the irradiation energy is 2 MeV, and the dose is 10" cm -2 Subsequently, the NV color center is generated by high-temperature vacuum annealing, and the temperature of the vacuum annealing furnace is maintained at 850 ° C for two hours, and the diamond nanoneedle array is placed in a volume ratio of 1: 1: 1 H ₂ SO ₄ : HNO ₃ : HC10 ₄ Heat in medium to boil to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with an oxygen terminal on the surface to ensure the stability of the negative potential of the NV color center.

Example 4 [0099] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1.

 [0100] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0101] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0102] A 5-10 micron thick diamond film layer was prepared on a l-5 cmxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface, and then the silicon wafer was ultrasonically cleaned for 10 minutes in an acetone solution, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution. Minutes; the cleaned silicon substrate is placed on a molybdenum substrate, placed in a C VD device, and evacuated to a temperature below 10 -5 p _a ; residual oxidation of the silicon surface by hydrogen plasma before film growth The layer and other impurities are washed again: Air pressure: 30 Torr, Microwave power: 1200 W, Silicon substrate temperature: 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, nucleation: 12 minutes. The specific parameters for (001) preferred orientation diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 20 hours;

 [0103] S12. Etching the diamond film layer to form a diamond nanoneedle array 2:

[0104] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, the substrate temperature is lowered to room temperature, the vacuum is evacuated to 10 5 Pa, and then the hydrogen is recharged to 7 mTorr, and the ECR microwave plasma mode is applied, and the electromagnetic is applied. The magnetic field provided by the coil has an intensity of 875 Gauss in the ECR zone. The specific parameters of reactive ion etching in the ECR-assisted microwave plasma are as follows: Hydrogen/argon flow: 11 sccm/9 sccm, total gas flow: 20 sccm, air pressure: 7xlO - ³ mTorr, microwave power: 800W, substrate plus DC negative bias -230V, etched dip is 4 hours; after the etching is completed, turn off the bias voltage, microwave power, electromagnetic coil power, turn off the gas, get Single crystal diamond nanoneedle array 2;

 [13105] S13. Growing a delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0106] Working directly in microwave plasma CVD after completion of reactive ion etching to prepare diamond nanoneedle array 2 The delta-tough diamond layer continues to grow in the mode; first, a high-purity epitaxial diamond layer 31 is grown on the surface of the diamond nanoneedle array 2, and ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process, in order to obtain higher Epitaxial mass, using very slow growth conditions, growth rate of about 10 nm / h, the specific process conditions are as follows: basic vacuum > 10 -6 ? &, substrate temperature 800. C, A hospital / hydrogen gas flow ratio: 1.5 sccm / 298 sccm, total gas flow 300 sccm, pressure 30 Torr, microwave power 1200 W, deposition time 10 minutes; then on the surface of high purity epitaxial diamond layer 31 nitrogen is miscellaneous Layer 32, using ¹⁵ N ₂ isotope gas (purity > 98%), the process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / nitrogen flow: 1.5 sccm / 258 sccm / 40 sccm, total gas flow: 300 sccm, pressure: 30 Torr, microwave power: 1200W, deposition time between 2 minutes; finally high-purity epitaxial diamond Layer 33, grown under conditions of: substrate temperature 800. C, A hospital / hydrogen gas flow ratio: 1.5 sccm / 298 sccm, total gas flow 300 sccm, pressure 30 Torr, microwave power 1200 W, deposition time 10 minutes; final growth diamond layer 31 / nitrogen miscellaneous layer 32 / diamond The structure of layer 33 is shown in Figures 2 and 3;

[1410] S14. Post-treatment to obtain a shallow NV center 3 diamond nanoneedle:

[0108] The diamond nanoneedle array 2 grown with the delta cryptic diamond layer in step S14 is irradiated by high energy electron beam to generate the vacancies required to form the NV color center 3, the irradiation energy is 2 MeV, and the dose is 10" cm -2 Subsequently, the NV color center is generated by high-temperature vacuum annealing, and the temperature of the vacuum annealing furnace is maintained at 850 ° C for two hours, and the diamond nanoneedle array is placed in a volume ratio of 1: 1: 1 H ₂ SO ₄ : HNO ₃ : HC10 ₄ Heat in medium to boil to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with an oxygen terminal on the surface to ensure the stability of the negative potential of the NV color center.

 Example 5

 [0110] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1.

 [0111] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0112] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0113] A 5-10 micron thick diamond film layer was prepared on a l-5 cmxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface. Then, the silicon wafer is ultrasonically cleaned in an acetone solution for 10 minutes, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution for 10 minutes; the cleaned silicon substrate is placed on a molybdenum substrate, and placed on In the C VD device, evacuate to 10 -5 p _a or less; before the film growth, the residual oxide layer and other impurities on the surface of the silicon wafer are cleaned again with hydrogen plasma: gas pressure: 30 Torr, microwave power: 1200 W, silicon substrate Temperature: 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, nucleation: 12 minutes. The specific parameters for (001) preferred orientation diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 20 hours;

[0114] S12. Etching the diamond film layer to form a diamond nanoneedle array 2:

[0115] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, the substrate temperature is lowered to room temperature, the vacuum is evacuated to 10 5 Pa, and then the hydrogen is recharged to 7 mTorr, and the ECR microwave plasma mode is applied, and the electromagnetic is applied. The magnetic field provided by the coil has an intensity of 875 Gauss in the ECR zone. The specific parameters of reactive ion etching in the ECR-assisted microwave plasma are as follows: Hydrogen/argon flow: 11 sccm/9 sccm, total gas flow: 20 sccm, air pressure: 7xlO - ³ mTorr, microwave power: 800W, substrate plus DC negative bias -230V, etched dip is 4 hours; after the etching is completed, turn off the bias voltage, microwave power, electromagnetic coil power, turn off the gas, get Single crystal diamond nanoneedle array 2;

 [0116] S13. Growing a delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0117] After the completion of the reactive ion etching to prepare the diamond nanoneedle array 2, the delta-disintegrating diamond layer is continuously grown in the microwave plasma CVD mode; firstly, a high-purity epitaxial diamond is grown on the surface of the diamond nanoneedle array 2. Layer 31, ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process. In order to obtain higher epitaxial quality, very slow growth conditions are used, and the growth rate is about 10 nm/h. The specific process conditions are as follows: Basic vacuum >10 -6 ? &, substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, deposition of 5 吋 between turns; then growth of silicon on the surface of high-purity epitaxial diamond layer 31 The impurity layer 32 is a 29 _Si H ₄ isotope gas (purity > 98%), and the silane gas used here is a silicon gas/hydrogen mixed dilution gas in which the concentration of the silane is 1%. The process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / silicon Alkane flow rate: 0.1 sccm/390 sccm/ 10 sccm, total gas flow rate: 400 sccm, gas pressure: 30 Torr, microwave power: 1200W, 1 hour after deposition of the crucible; finally high-purity epitaxial diamond layer 33, growth conditions To: substrate temperature 800. C, A hospital / hydrogen gas flow ratio: 0.1 sccm / 400 sccm, total gas flow 400 sccm, pressure 30 Torr, microwave power 1200 W, 10 吋 between depositions; final growth diamond layer 31 / silicon miscellaneous layer 32 / The structure of the diamond layer 33 is as shown in Figures 2 and 3;

[141] S14. Post-treatment to obtain a shallow NV center 3 diamond nanoneedle:

[0119] The diamond nanoneedle array 2 grown with the delta cryptic diamond layer in step S14 is irradiated by high energy electron beam to generate the vacancies required to form the SiV color center 3, the irradiation energy is 2 MeV, and the dose is 10 ¹⁴ cm -2 The SiV color center is then produced by high temperature vacuum annealing, and the vacuum annealing furnace temperature is maintained at 850. C two small crucibles, the diamond nanoneedle array was placed in a volume ratio of 1: 1: 1 H ₂ SO ₄ : HNO ₃ : HC10 ₄ was heated and boiled to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with an oxygen termination on the surface to ensure the stability of the negative potential of the SiV color center.

 Example 6

 [0121] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1.

 [0122] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0123] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0124] A 5-10 micron thick diamond film layer was prepared on a l-5 cmxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface, and then the silicon wafer was ultrasonically cleaned for 10 minutes in an acetone solution, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution. Minutes; the cleaned silicon substrate is placed on a molybdenum substrate, placed in a C VD device, and evacuated to a temperature below 10 -5 p _a ; residual oxidation of the silicon surface by hydrogen plasma before film growth The layer and other impurities are washed again: Air pressure: 30 Torr, Microwave power: 1200 W, Silicon substrate temperature: 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, shape Interpolation: 12 minutes. The specific parameters of (001) preferred oriented diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 20 hours;

[0125] S 12. Etching the diamond film layer to form a diamond nanoneedle array 2:

[0126] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, the substrate temperature is lowered to room temperature, the vacuum is evacuated to 10 ⁵ Pa, and then the hydrogen is recharged to 7 mTorr, and the ECR microwave plasma mode is applied, and the electromagnetic is applied. The magnetic field provided by the coil has an intensity of 875 Gauss in the ECR zone. The specific parameters of the reactive ion etching in the ECR-assisted microwave plasma are as follows: Hydrogen/argon flow: 1 1 sccm/9 sccm, total gas flow: 20 sccm, air pressure : 7x lO - ³ mTorr, microwave power: 800W, substrate plus DC negative bias -230V, 4 turns after etching; after biasing, turn off bias voltage, microwave power, electromagnetic coil power, turn off gas , obtaining a single crystal diamond nanoneedle array 2;

 [13.] S 13. Growth of the delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0128] After the completion of the reactive ion etching to prepare the diamond nanoneedle array 2, the delta-disintegrating diamond layer is continuously grown in the microwave plasma CVD mode; firstly, a high-purity epitaxial diamond is grown on the surface of the diamond nanoneedle array 2. Layer 31, ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process. In order to obtain higher epitaxial quality, very slow growth conditions are used, and the growth rate is about 10 nm/h. The specific process conditions are as follows: Basic vacuum > 10 -6 ? &, substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.2 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, deposition of 5 吋 between turns; then growth of nitrogen on the surface of high-purity epitaxial diamond layer 31 The impurity layer 32 is made of i iB isotope trimethylborane gas (purity >98%), and the trimethylborane gas used here is a dilution gas of trimethylboron/hydrogen mixed gas, wherein trimethylborane The concentration is 0.1%. The process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / trimethylborane flow: 0.1 sccm / 390 sccm / 10 sccm, total gas flow: 400 sccm, pressure: 30 Torr, microwave power: 1200W, 1 hour after deposition; finally The high-purity epitaxial diamond layer 33 is grown under the conditions of a substrate temperature of 800. C, A hospital / hydrogen gas flow ratio: 0.2 sccm / 400 sccm, total gas flow 400 sccm, pressure 30 Torr, microwave power 1200 W, 10 吋 between depositions; final growth diamond layer 31 / boron miscellaneous layer 32 / The structure of the diamond layer 33 is as shown in Figures 2 and 3;

[0129] S 14. Post-treatment to obtain a diamond nanoneedle of a shallow NV center 3: [0130] The diamond nanoneedle array 2 grown with the delta miscellaneous diamond layer in step S14 is irradiated by high energy electron beam to generate the vacancies required to form the BV color center 3, the irradiation energy is 2 MeV, and the dose is 10" cm -2 Subsequently, the BV color center is generated by high-temperature vacuum annealing, and the temperature of the vacuum annealing furnace is maintained at 850 ° C for two hours, and the diamond nanoneedle array is placed in a volume ratio of 1:1:1 H ₂ SO ₄ :HNO ₃ :HC10 ₄ Heat in medium to boil to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with an oxygen terminal on the surface to ensure the stability of the negative potential of the BV color center.

 Example 7

 [0132] This embodiment provides a diamond nanoneedle structure and a preparation method thereof. The structure of the diamond nanoneedle structure is as shown in FIG. 4, which comprises a diamond base layer 1 and a plurality of diamond nanoneedle 2 arrays extending on the surface of the diamond base layer 1, the adjacent diamond nanoneedles 2 are spaced apart from each other, and The side surface of the diamond nanoneedle 2 is perpendicular to the surface of the diamond base layer 1, and the color center structure 3 is also distributed in the surface layer of the diamond nanoneedle 1.

 [0133] The preparation method of the diamond nanoneedle structure of this embodiment is as follows:

 [0134] S11. Preparing a preferentially oriented diamond film layer deposited on the surface of the silicon substrate:

[0135] A 5-10 micron thick diamond film layer was prepared on a l-5 cmxl-5 cm, (001) silicon wafer by microwave plasma CVD. Before the growth, the silicon wafer was placed in a hydrofluoric acid solution for 2 minutes to remove the oxide layer on the surface, and then the silicon wafer was ultrasonically cleaned for 10 minutes in an acetone solution, ultrasonically cleaned in deionized water for 10 minutes, and ultrasonically cleaned in an alcohol solution. Minutes; the cleaned silicon substrate is placed on a molybdenum substrate, placed in a C VD device, and evacuated to a temperature below 10 -5 p _a ; residual oxidation of the silicon surface by hydrogen plasma before film growth The layer and other impurities are washed again: Air pressure: 30 Torr, Microwave power: 1200 W, Silicon substrate temperature: 800. C, 30 minutes in the daytime. Subsequently, the diamond film nucleation stage is started. The specific parameters of the microwave plasma CVD are as follows: A hospital/hydrogen flow: 10 sccm/190 sccm, total gas flow: 200 sccm, air pressure: 16 Torr, microwave power: 800 W, silicon lining Bottom temperature: 800. C, substrate negative bias: -150 V, nucleation: 12 minutes. The specific parameters for (001) preferred orientation diamond film growth in microwave plasma CVD are: A hospital / hydrogen flow: 1.5 sccm / 298 sccm, total gas flow: 300 sccm, gas pressure: 30 Torr, microwave power: 1200 W, silicon lining Bottom temperature: 850. C, deposition day: 20 hours;

 [0136] S12. Etching the diamond film layer to form a diamond nanoneedle array 2:

[0137] After the growth of the diamond thick film is finished, the microwave power source and the gas source are turned off, the substrate temperature is lowered to room temperature, the vacuum is evacuated to 10 ⁵ Pa, and then the hydrogen is recharged to 7 mTorr, and the ECR microwave plasma mode is applied, and the electromagnetic is applied. Coil The intensity of the magnetic field provided in the ECR zone is 875 Gauss. The specific parameters of the reactive ion etching in the ECR assisted microwave plasma are as follows: Hydrogen/argon flow: 11 sccm/9 sccm, Total gas flow: 20 sccm, Air pressure: 7xlO - ³ mTorr, microwave power: 800W, substrate with DC negative bias -230V, etched for 4 hours; after switching, turn off bias, microwave power, solenoid power, shut off gas, get single Crystal diamond nanoneedle array 2;

[13138] S13. Growing a delta miscellaneous diamond layer on the surface of the diamond nanoneedle array 2:

[0139] After the completion of the reactive ion etching to prepare the diamond nanoneedle array 2, the delta-disintegrating diamond layer is continuously grown in the microwave plasma CVD mode; first, a high-purity epitaxial diamond is grown on the surface of the diamond nanoneedle array 2. Layer 31, ¹² CH ₄ isotope gas (purity 99.999%) is used in the growth process. In order to obtain higher epitaxial quality, very slow growth conditions are used, and the growth rate is about 10 nm/h. The specific process conditions are as follows: Basic vacuum >10 -6 ? &, substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, 10 吋 between depositions; then phosphorus growth on the surface of high-purity epitaxial diamond layer 31 The impurity layer 32 is made of 13⁄4 ₄ isotope gas (purity >98%), and the silane gas used here is a phosphorus gas/hydrogen mixed dilution gas in which the concentration of phosphane is 1%. The process conditions for the cumbersome growth are: substrate temperature 800. C, A hospital / hydrogen / phosphine flow: 0.1 sccm / 390 sccm / 10 sccm, total gas flow: 400 sccm, pressure: 30 Torr, microwave power: 1200W, 1 hour after deposition; finally high purity The epitaxial diamond layer 33 is grown under the following conditions: substrate temperature 800. C, A hospital/hydrogen gas flow ratio: 0.1 sccm/400 sccm, total gas flow 400 sccm, air pressure 30 Torr, microwave power 1200 W, 10 吋 between depositions; final growth diamond layer 31/phosphorus miscellaneous layer 32/ The structure of the diamond layer 33 is as shown in Figures 2 and 3;

 [1440] S14. Post-treatment to obtain a shallow PV center 3 diamond nanoneedle:

[0141] The diamond nanoneedle array 2 grown with the delta cryptic diamond layer in step S14 is subjected to high energy electron beam irradiation to generate the vacancies required to form the PV color center 3, the irradiation energy is 2 MeV, and the dose is 10" cm -2 Subsequently, the PV color center is generated by high-temperature vacuum annealing, and the temperature of the vacuum annealing furnace is maintained at 850 ° C for two hours, and the diamond nanoneedle array is placed in a volume ratio of 1: 1: 1 H ₂ SO ₄ : HNO ₃ : HC10 ₄ Heat in medium to boil to 200.

 C, hold for more than 30 minutes, and obtain a diamond nanoneedle with oxygen terminal on the surface to ensure the stability of the negative potential of the PV color center.

[0142] Related performance test: The diamond nanoneedle structures provided in the above Examples 1-7 were tested separately for the relevant properties in Table 1 below:

 [0144] Table 1

 It can be seen from the above Table 1 that the diamond nanoneedle structure provided by the embodiment of the present invention has a high aspect ratio, excellent fluorescence luminescence property and electron spin coherence property, and can be used for the device for delivering substances to cells in the embodiment of the present invention. Through the cell membrane to achieve the transmission and detection of substances in the cell, it can also provide a guarantee for a wide range of applications in biomedical fields such as biosensing and bioimaging.

 The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

 Claim  [Claim 1] A diamond nanoneedle structure comprising a diamond substrate layer and a plurality of diamond nanoneedles extending on a surface of the diamond substrate layer, wherein: the adjacent diamond nanoneedles are spaced apart from each other, and The diamond nanoneedle is perpendicular to the surface of the diamond substrate layer, and a color center structure is also distributed in the diamond nanoneedle surface layer.  [Claim 2] The diamond nanoneedle structure according to claim 1, wherein: the color center structure has a density of 1-5000/needle distributed on the surface of the diamond nanoneedle; and/or the color The distance between the core structure and the surface of the diamond nanoneedle is less than or equal to 100 nm; and / the color center structure is a color center structure formed by at least one of N, Si, P, and B. [Claim 3] The diamond nanoneedle structure according to claim 1 or 2, wherein the diamond nanoneedle has a diameter of 100 to 2000 nm, a height of 2 to 10 μm _, or a aspect ratio of 10 to 70. [Claim 4] A method for preparing a diamond nanoneedle structure, comprising the following steps:  Etching the diamond film layer to form a plurality of diamond nanoneedles, the diamond nanoneedles being spaced apart from each other;  Forming a first pure diamond layer, a delta-dense layer and a second pure diamond layer on the surface of the diamond nanoneedle;  The diamond nanoneedles on which the delta-taste layer is grown are subjected to electron beam irradiation treatment and then annealed in a protective atmosphere. [Claim 5] The preparation method according to claim 4, wherein: the first pure diamond layer, the second pure diamond layer, and the delta-taste layer are deposited by a CVD method, wherein The conditions for growing the delta-difficult layer are: The base vacuum is >10 - 6 _Pa and the substrate temperature is 600~900. C, a mixed gas total flow rate of the diamond carbon source gas/hydrogen/chaotic element gas: 200 to 2000 sccm, a volume percentage of the diamond carbon source gas of 0.01 to 0.5%, and a volume percentage of the hydrogen of 80 to 99%, The mass ratio of miscellaneous elements and carbon elements is l^ O^ , gas pressure: 20 40 Torr, microwave power: 500~1200W, deposition time between 5~30 minutes; conditions for growing the first pure diamond layer and/or the second pure diamond layer are: The base vacuum is >10 - 6 _Pa and the substrate temperature is 600~900. C, total flow of mixed gas of diamond carbon source gas/hydrogen: 200~2000 Sccm, wherein the volume percentage of diamond carbon source gas is 0.01~0.5%, the volume percentage of hydrogen is 99.5~99.9<3⁄4, the pressure is 20 40 Torr, the microwave power is 500~1200W, and the deposition time is 2-20 hours. The preparation method according to claim 5, wherein the impurity element is at least one of N, Si, P, and B. The preparation method according to claim 6, wherein the N miscellaneous element is ¹⁵ N The Si source of the Si impurity element is at least one of silane, trimethylsilane, and ethyl orthosilicate; the P source of the P impurity element is phosphine, trimethylsilyl phosphate, and phosphoric acid At least one of methyl esters; The B source of the B impurity element is at least one of diborane, trimethylborane, and trimethyl borate. The method according to claim 5, wherein the diamond carbon source gas is at least one of methane, acetylene, acetone, and ethanol. The preparation method according to any one of claims 5-8, wherein: the irradiation energy of the electron beam irradiation treatment is 2 to 4 MeV, and the dose is (1 to 9) x lO ¹⁴ cm ² ; and/or The annealing treatment temperature is 800 to 1000. ^c , the daytime is 2~4 hours. The preparation method according to any one of claims 5 to 8, wherein after the annealing of the diamond nanoneedles, the step of oxidizing the diamond nanoneedles in an acid solution is further included. The preparation method according to claim 10, wherein the oxidizing treatment is performed by placing the annealed diamond nanoneedle in a mixed acid solution and heating and boiling to 20 to 350. C, maintaining for more than 30 minutes, wherein the mixed acid solution comprises a volume ratio of 1: (1-3) : (1-3) A mixed acid of H ₂ S0 ₄ , HNO ₃ and HC _{10 4} . The preparation method according to any one of claims 5-8 to 11, characterized in that: The method of etching the corundum film layer is as follows:  The diamond film layer is subjected to ECR-assisted microwave plasma etching or ICP etching; wherein the conditions of the ECR-assisted microwave plasma etching are: Total gas flow: 20 sccm, etching gas 11 ₂ Volume fraction 50~100<3⁄4, Ar volume fraction 0~50<3⁄4, pressure: (5-8)xl0 - ³ mTorr, microwave power: 700-1000W, substrate plus DC negative bias -190~-230V, The etching time is 2-8 small turns, and the magnetic field strength of the ECR area is 875 Gauss;  The conditions of the ICP etching are: Use hydrogen, argon, oxygen, helium, nitrogen, gaseous carbon source, CF ₄ , C ₄ F

One or more of ₆ are reaction gases, the flow rate of the reaction gas is 5 to 200 s _CC m , the reaction gas pressure is 0.1 to 10 Pa, the power of the plasma is 500 to 3000 W, and the RF power on the substrate stage is 50~ 300W, etched between 10~600 min. [Claim 13] The preparation method according to claim 12, wherein the etching gas is one or a mixture of two or more of hydrogen, argon, oxygen, CF ₄ , and SF ₆ . [Claim 14] The preparation method according to claim 12, wherein the diamond film layer is an electron-grade purity diamond flake or a preferentially oriented polycrystalline diamond thick film. [Claim 15] Use of a diamond nanoneedle structure according to any of claims 1-4 in a fluorescent luminescent probe, a biosensing, and a device for delivering a substance to a cell.