TWI722484B - Electrochemical sensor with three-dimensional structure electrodes - Google Patents

Abstract

An electrochemical sensor with three-dimensional structure electrodes includes an upper cover, a substrate and a central spacer. The upper cover has a sample inlet hole, an auxiliary electrode and a reference electrode. The substrate has a working electrode disposed on an opposite side of the auxiliary electrode. A bioprobe is attached to the working electrode. The central spacer is disposed between the substrate and the upper cover, and has a through hole matched to the sample inlet hole. The three-electrode arrangement of the 3D structure of the present invention can recover and reuse the expensive working electrode.

Description

Electrochemical sensor with three-dimensional structure electrode

The invention relates to an electrochemical sensor, in particular to an electrochemical sensor with a three-dimensional structure electrode.

In recent years, people pay more attention to the quality of life and physical health, so the monitoring and data collection of the living environment, diet, animal and plant, and personal health have become more and more important, which has made the biochemical detection technology flourish in the past few years. Today’s biochemical laboratory uses liquid chromatography (LC), enzyme immunoassay (ELISA), reverse transcription polymerization chain reaction (RT-PCR) and other technologies. Although these analytical methods have the advantages of high accuracy and good selectivity, the equipment Expensive, pre-purification treatment is time-consuming and not suitable for on-site real-time monitoring. Compared with other detection methods, electrochemical sensing systems have the advantages of sensitivity, miniaturization, and low energy consumption. The most common example of electrochemical sensing systems is a blood glucose meter. Most blood glucose meters on the market use screen printing technology to make three-electrode disposable test strips. However, the process accuracy of screen printing is low, and it will not be able to meet the increasingly stringent measurement accuracy requirements. In order to solve this problem, some manufacturers have used precious metals such as gold and platinum as working electrodes, which have the advantages of biocompatibility and good process-scale precision control. However, the current design of integrating the reference electrode (silver Ag/silver chloride AgCl) and the auxiliary electrode (graphite graphite) of different materials in the 2D plane is not conducive to recycling after use. Therefore, expensive precious metal materials are wasted and the waste treatment process is complicated.

FIG. 1 is a schematic diagram of the planar arrangement of three electrodes of a conventional electrochemical sensor. The substrate 1 has an auxiliary electrode 2, a reference electrode 4, and a working electrode 6. The working electrode 6 uses a precious metal such as pure gold as an electrode material. When the conventional electrochemical sensor is used, since the three electrodes are located on the same substrate, it is difficult to recover the working electrode separately for reuse. In order to solve the above problems, it is necessary to separately fabricate the working electrode on a substrate. The surface of the pure gold working electrode after use can be cleaned by wet or dry cleaning, and recycled and reused.

The purpose of the present invention is to provide an electrochemical sensor with a three-dimensional structure electrode. The working electrode is arranged on the opposite surface of the auxiliary electrode, and a spacer is used to define the relative distance in the middle. After the sensor is used, the upper cover and the middle septum can be easily removed, and the gold working electrode surface on the substrate is cleaned wet or dry, and then recycled and reused.

In order to achieve the above objective, the present invention provides an electrochemical sensor with a three-dimensional structure electrode, which includes an upper cover, a substrate and a middle spacer. The upper cover has a sample entry hole, an auxiliary electrode and a reference electrode. The substrate has a working electrode arranged on the opposite surface of the auxiliary electrode, and a biological probe is connected to the working electrode. The middle spacer is arranged between the base plate and the upper cover, and has a through hole that matches the sample entry hole.

Compared with the conventional electrochemical sensor, the present invention has the following advantages: 1. The present invention uses pure gold or platinum as the working electrode, the process is stable, the size is easy to control, and the accuracy is good when performing electrochemical measurement. 2. The three-electrode arrangement of the 3D three-dimensional structure of the present invention can recycle and reuse expensive working electrodes. 3. The innovative 3D three-dimensional structure of the electrochemical sensor of the present invention can effectively reduce the demand for samples. 4. The working electrode and the auxiliary electrode of the present invention face each other, and the electric force generated by the electromotive force is distributed longitudinally, which is more uniform and concentrated than the traditional horizontally distributed electric force.

In the present invention, a pure gold working electrode fixed with biological probes (such as enzymes, antibodies, antigens or nucleic acids) and other auxiliary and reference electrodes are respectively fabricated on two substrates. Among them, a middle spacer is attached to the two substrates to form a 3D three-dimensional structure. The biological probes attached to the used pure gold working electrode can be removed by wet or dry methods. The cleaned gold electrode can then be joined and fixed with a new biological probe, so that the expensive pure gold working electrode can be reused.

Figure 2 is an exploded view of the electrochemical sensor with three-dimensional structure electrodes of the present invention. As shown in the figure, the electrochemical sensor 100 has an upper cover 10, a middle spacer 20 and a substrate 30. The upper cover 10 has a sample entry hole 12, an auxiliary electrode 14 and a reference electrode 16. The material of the auxiliary electrode 14 is silver or silver chloride. The material of the reference electrode 16 is graphite.

The middle spacer 20 is disposed between the base plate 30 and the upper cover 10 and has a through hole 22 that matches the sample entrance hole 12. The substrate 30 has a working electrode 32 which is arranged on the opposite surface of the auxiliary electrode 14 in the combined electrochemical sensor 100. The working electrode of the present invention can also be a plurality of working electrodes 34 arranged on the substrate 40. A biological probe 36 is attached to the working electrode 32. The plurality of working electrodes 34 are each connected to the biological probe 38, and the appearance of the plurality of working electrodes 34 may be in the form of an array. The shape of the working electrodes 32 and 34 is circular or polygonal, and the material is pure gold or platinum. The working electrodes 32 and 34 have electrical plugs 42, 44, respectively. The biological probes 36 and 38 are biological probes for enzymes, antibodies, antigens, or nucleic acids. The function of the sample entry hole 12 and the through hole 22 is to allow the sample such as saliva, blood or urine to pass through and be attached to the working electrodes 32 and 34. The material of the upper cover 10 and the spacer 20 may be polyethylene terephthalate PET. The auxiliary electrode 14, the reference electrode 16, the working electrodes 32, 34 and their circuits can be made by screen printing or 3D printing.

Figure 4 is an assembly diagram of the electrochemical sensor with three-dimensional structure electrodes of the present invention. As shown in the figure, the electrochemical sensor 100 has an upper cover 10, a middle spacer 20 and a substrate 30. The upper cover 10 has a sample entry hole 12, an auxiliary electrode 14 and a reference electrode 16. The substrate 30 has a working electrode 32. The working electrode 32 and the auxiliary electrode 14 face each other. When the electrochemical sensor 100 is performing the detection operation, the electric force lines 50 generated by the electromotive force of the working electrode 32 and the auxiliary electrode 14 are longitudinally distributed. The longitudinally distributed power lines 50 are more uniform and concentrated than the traditional horizontally distributed power lines, so more accurate detection data can be obtained.

The working electrodes 32, 34 of the electrochemical sensor with a three-dimensional structure electrode of the present invention can use wet or dry cleaning methods to remove the biological probes 36, 38, and the cleaned working electrodes 32, 34 can be joined to fix new ones. Biological probe. The wet cleaning method uses sulfuric acid and hydrogen peroxide as a cleaning agent. The dry cleaning method uses Ar Plasma or ultraviolet rays and ozone as a cleaning agent. After the gold electrode of the electrochemical sensor with three-dimensional structure electrode of the present invention is actually tested, its surface is subjected to X-ray photoelectron spectroscopy (XPS) chemical composition qualitative analysis and quantitative analysis. The analysis results show that many carbon C, Organic substances such as nitrogen N and oxygen O. The gold electrode with carbon C, nitrogen N, and oxygen O organic substances on the surface is cleaned with argon plasma. The cleaned gold electrode is subjected to X-ray photoelectron spectroscopy (XPS) chemical composition analysis, and it is found that the organic substances on the surface have been completely removed. Pay one hundred percent of the gold.

22 Through hole 100 Electrochemical sensors 10 Top cover 12 The sample entry hole 2.14 Auxiliary electrode 4. 16 Reference electrode 20 Separator 1, 30, 40 Substrate 6, 32, 34 Working electrode 50 Power lines 36, 38 Biological probes 42, 44 Electric plug

Figure 1 is a schematic diagram of a 2D planar arrangement of three electrodes of a conventional electrochemical sensor. Figure 2 is an exploded view of the electrochemical sensor with three-dimensional structure electrodes of the present invention. Figure 3 is a schematic diagram of a plurality of working electrodes of the electrochemical sensor with three-dimensional structure electrodes of the present invention. Figure 4 is an assembly diagram of the electrochemical sensor with three-dimensional structure electrodes of the present invention.

100 electrochemical sensor 10 Upper cover 12 Sample entry hole 14 Auxiliary electrode 16 Reference electrode 20 septum 30 Substrate 32 Working electrode 50 Power line

Claims (8)

An electrochemical sensor with a three-dimensional structure electrode, comprising: a top cover with a sample entry hole, an auxiliary electrode and a reference electrode; a substrate with a working electrode arranged on the opposite surface of the auxiliary electrode, the working A biological probe is attached to the electrode, and the working electrode can be removed by wet or dry cleaning. The cleaned working electrode can be attached and fixed to a new biological probe; and a septum arranged in A through hole is provided between the substrate and the upper cover to match the sample entry hole. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the material of the substrate is silicon, glass, ceramic or polymer. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the material of the working electrode is pure gold or platinum. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the shape of the working electrode is a circle or a polygon. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the appearance of the working electrode is in the form of an array. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the biological probe is an enzyme, antibody, antigen or nucleic acid biological probe. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the wet cleaning method uses sulfuric acid and hydrogen peroxide as a cleaning agent. The electrochemical sensor with a three-dimensional structure electrode according to claim 1, wherein the dry cleaning method uses argon plasma or ultraviolet rays and ozone as a cleaning agent.

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