CN1437018A - Prepn of capillary electrophoresis chip for biochemical analysis - Google Patents

Abstract

The preparation process of capillary electrophoresis chip for biochemical analysis includes selecting organic glass material, machining channels with a mechanical scoring instrument, drilling through holes in proper positions, smoothing channels and surface modification, adhering to connect two sheets of organic glass plates with organic solvent to enclose the channels. The said process of the present invention has low production cost, simple production process and high qualified product rate and is suitable for mass production.

Description

Preparation method of capillary electrophoresis chip for biochemical analysis

(1) Technical field

The invention relates to a method for preparing an integrated capillary electrophoresis chip for biochemical analysis.

(2) Background technology

Capillary electrophoresis technology has developed rapidly since the 1990s. In just a few years, it has completed the transition from laboratory technology to commercial technology, from small molecule analysis to biomacromolecule analysis, from simple separation modes to multiple separation modes and technologies, and from large-scale Several leaps from instrumentation to miniaturization. The integrated capillary electrophoresis chip (ICEC) based on the capillary structure combines biotechnology, microelectronics technology and MEMS technology to integrate various channels, electrode slots, detection flow cells, etc. on the same substrate (silicon wafer, glass or Ultra-high-speed electrophoresis apparatus inside plexiglass). Most of the chips produced at this stage adopt the standard microelectronics processing process with glass as the substrate, that is, photolithography → corrosion → punching holes → bonding. The process is relatively complicated, the yield is low, and the cost is relatively high.

In recent years, plexiglass (polymethylmethacrylate, PMMA) occupies an increasing proportion in the field of capillary electrophoresis chips because of its low cost and easy processing, and it is also the main development direction of ICEC. The chemical name of plexiglass is polymethyl methacrylate (CH2CH3(CO)2CH3)n, which is polymerized from monomer polymethyl methacrylate. Sunlight, the ability to pass through ultraviolet rays reaches 73%), which can be compared with ordinary silicate plexiglass; plexiglass is a thermoplastic, its main performance feature is light weight, relative density is 1.19, its weight is only that of plexiglass Half, 43% of aluminum; followed by its high mechanical strength, this is because it has a branched linear polymer, that is, has a soft macromolecular segment, and its tensile strength is 60-70MPa , the impact strength is 1.2-1.37MPa/cm ² , which is 7-18 times that of inorganic glass; finally, organic glass has certain heat resistance and begins to soften at a temperature of 140°C. At present, the methods of using plexiglass to make integrated capillary electrophoresis chips for biochemical analysis mainly include injection molding, wire printing, silicon wafer printing, and laser ablation. The injection molding method is to first make a negative plate with the method of making a silicon wafer, then use this negative film to make a chrome mother plate, then use this mother plate to make a sub-plate, and finally use the sub-plate as a mold, and use the injection molding Many plastic chips are produced by the method. The bonding temperature is 105°C, the time is 5 minutes, the adhesive is Mylar (Top Flight Monokote, Champaign, IL), and the thickness is 2mm; the wire stamping method is about 20cm long and 13-25μm in diameter. - The two ends of the Cr alloy are fixed on a metal bow to make it taut, and placed on a PMMA sheet with a width of 2 cm, a length of 10 cm, and a thickness of 1.6 cm that has been cleaned with an antistatic brush in advance, and a glass carrier is also added to the metal wire. Then cover the two glass slides completely with two aluminum blocks, clamp the aluminum blocks, put them in the furnace, heat at 105°C for 10 minutes, make the metal wires form grooves on the PMMA, take out the whole piece to cool, and take out After removing the aluminum block and the glass slide, pull out the wire, and bond the bottom plate and the cover plate at 108°C for 10 minutes; the silicon wafer printing method is to place the silicon negative film made between two smooth aluminum plates , put a PMMA sheet cleaned with an antistatic brush between the silicon sheet and the aluminum sheet, and then clamp it with the aluminum sheet, heat it to 135°C, take it out after 5 minutes and cool it down, and use heat for the bonding process, as described above The laser ablation method is to shoot a high-intensity laser from the mask to the PMMA, and instantly ablate it into the desired shape at a specific position, and then refer to the above method to bond the cover plate and the negative.

(3) Contents of the invention

The purpose of the present invention is to provide a method for preparing a capillary electrophoresis chip for biochemical analysis, which has a simple process and is beneficial to improving product quality.

The purpose of the present invention is achieved like this:

(1) The substrate material of the chip is plexiglass;

(2) the plexiglass is placed on the micro-channel processing machine, and the micro-channel is drawn on the plexiglass substrate with the marking cutter head;

(3) Surface treatment of the microchannel: inject a mixed solution of 2-4:1 chloroform and glacial acetic acid into the microchannel until the solution volatilizes to smooth the surface of the microchannel, and use 5-15% acrylic acid The aqueous solution is grafted for 5-15 minutes, modified with a mixture of 60-80% N-methyl silicone oil and 20-40% ethyl acetate for 5-20 minutes, and left for 12-24 hours for aging treatment ;

(4) Drill through holes on the chip with the processed micro-channel, and the hole diameter is between 0.3 and 2 mm;

(5) bonding the processed chip to another piece of organic glass with a mixed solution of chloroform, glacial acetic acid and ethanol in a ratio of 5 to 7:1 to 2:1 to make a product.

The present invention has the advantages of: 1. Adopt organic glass as the processing substrate material, which has higher cost-effectiveness in material selection than chips with glass as the substrate material; 2. Adopt the mechanical processing method to process the microchannel, The size and shape of the channel can be controlled, and the shape of the pattern can be changed according to the needs, which is more convenient and flexible than the photolithography plate-making method, and the cost is greatly reduced; There is no other processing technology on a piece of plexiglass, which reduces the difficulty of alignment; 4. The solution is injected into the channel, and the surface of the channel becomes smooth with the volatilization of the solution, which improves the leveling of the fluid flow in the channel, and the channel The surface is smooth, which can improve the separation effect of electrophoresis. The surface is grafted and modified to reduce the surface energy and improve the reaction inertness. 5. The preparation method does not require complex process equipment, the processing process is simplified, the production cost is reduced, and the processing yield is high.

(4) Description of drawings

Fig. 1 is the straight channel chip processing diagram in embodiment 1;

Fig. 2 is the processing diagram of the curved channel chip with curved corner and curved shape in embodiment 2;

Fig. 3 is a structural schematic diagram of a micro-channel processing machine.

(4) Specific implementation plan

The following examples describe the present invention in more detail:

Example 1:

This embodiment is for processing the simple straight channel form shown in FIG. 1 . Firstly, the plexiglass is processed into the required chip size, such as 25*50mm ² , and the surface is ultrasonically cleaned with deionized water; the straight channel is processed with a micro-channel processor. Referring to Figure 3, the composition of the micro-groove processing instrument includes a base 3, a cutter head bracket 1 installed on the base, an X-direction workbench 6, a Y-direction workbench 5, and a sliding carving cutter head installed on the cutter head holder. 7. There is a Z-direction adjustment button 8 on the sliding carving cutter head, an X-direction adjustment button 2 on the X-direction workbench, and a Y-direction adjustment button 4 on the Y-direction workbench. On the chip substrate, use the X-axis of the micro-channel processing instrument to control the lateral displacement, the Y-axis to control the longitudinal displacement, and the Z-axis to control the scribing depth, and process a micro-channel with a depth of 30 μm and a width of 100 μm;

Treat the surface of the plexiglass chip substrate after scribing:

First, the surface of the microchannel was smoothed with a 2:1 mixed solution of chloroform and glacial acetic acid. The solution is injected into the microchannel, and the surface of the microchannel becomes smooth with the volatilization of the solution, so as to improve the leveling of the fluid flow in the channel;

On the other hand, the surface is grafted and modified to reduce the surface energy and improve the reaction inertness. The specific modification is as follows: (1) Treat with 8-10% acrylic acid aqueous solution for 10 minutes. (2) Treatment with a mixture of 70% N-methyl silicone oil and 30% ethyl acetate for 15 minutes; (3) Aging and standing for 20-24 hours;

After the microchannel is processed and manufactured, holes are punched on the chip to serve as sample pools, buffer sample pools, waste liquid pools, and sample recovery pools. First use a drill with a radius of 0.5mm to open it, and then use a drill with a radius of 1.0mm to drill half of the thickness of the organic glass slide, which can meet the requirements for inserting the pipette and ensure the sealing condition;

Adhesive treatment, seal the channel: (1) Surface treatment: use ultrasonic cleaning, use electronic cleaning agent DZ-1 and DZ-2 to configure 1# and 2# lotion respectively, use standard cleaning process, and then chip The substrate is placed in an oven, and the chip is dried at 60°C; (2) Coating of the solvent: it must be smooth and uniform, otherwise internal stress will be generated at the interface due to uneven shrinkage; (3) Bonding : Use chloroform or the like as an adhesive to bond two glass slides.

Example 2

First process the plexiglass into the required chip size, such as 25*50mm ² , and ultrasonically clean the surface with deionized water;

Use the micro-groove processing instrument to process the straight channel, and use the instrument to control the lateral displacement on the X-axis, the longitudinal displacement on the Y-axis, and the scribe depth on the Z-axis on the chip substrate, and process a micro-groove with a depth of 30 μm and a width of 100 μm road;

Treat the surface of the plexiglass chip substrate after scribing:

First, the surface of the microchannel was smoothed with a 3:1 mixed solution of chloroform and glacial acetic acid. The solution is injected into the microchannel, and the surface of the microchannel becomes smooth with the volatilization of the solution, so as to improve the leveling of the fluid flow in the channel;

On the other hand, the surface is grafted and modified to reduce the surface energy and improve the reaction inertness. The specific modification is as follows: (1) Treat with 9% acrylic acid aqueous solution for 15 minutes. (2) Treat with a mixture of 60% N-methyl silicone oil and 40% ethyl acetate for 20 minutes; (3) Aging and leave for 20 hours;

After the microchannel is processed and manufactured, holes are punched on the chip to serve as sample pools, buffer sample pools, waste liquid pools, and sample recovery pools. First use a drill with a radius of 0.5mm to open it, and then use a drill with a radius of 1.0mm to drill half of the thickness of the organic glass slide, which can meet the requirements for inserting the pipette and ensure the sealing condition;

Adhesive treatment, seal the channel: (1) Surface treatment: use ultrasonic cleaning, use electronic cleaning agent DZ-1 and DZ-2 to configure 1# and 2# lotion respectively, use standard cleaning process, and then chip The substrate is placed in an oven, and the chip is dried at 60°C; (2) Coating of the solvent: it must be smooth and uniform, otherwise internal stress will be generated at the interface due to uneven shrinkage; (3) Bonding : Use chloroform or the like as an adhesive to bond two glass slides.

Example 3

This embodiment is to process the curved channel form shown in Fig. 2 with an angle turn, and the processing process is basically the same as that in embodiment 1, only the channel marking program is changed accordingly during the process of channel processing.

Claims (5)

1, a kind of preparation method who is used for the capillary electrophoresis chip of biochemical analysis is characterized in that:

1.1 the backing material of chip is an organic glass;

1.2 organic glass is placed on little raceway groove processing machine, on the organic glass substrate, depicts little raceway groove with the delineation cutter head;

1.3 little raceway groove is carried out surface treatment,

1.3.1 with 2～4: 1 the methenyl choloride and the mixed solution of glacial acetic acid inject little raceway groove, little channel surface are carried out smooth treatment to solution evaporation,

Handled 5-15 minute 1.3.2 carry out grafting with 5～15% acrylic acid aqueous solution,

1.3.3 carrying out modification, N-methyl-silicone oil with 60～80% and 20～40% ethyl acetate mixture handled 5～20 minutes,

Carried out the ageing processing in 12～24 hours 1.3.4 place;

1.4 get through the hole machining on the chip of little raceway groove, the aperture is between 0.3～2mm;

1.5 the chip that processing is handled well and another piece organic glass are with 5～7: the mixed solution of 1～2: 1 methenyl choloride, glacial acetic acid and ethanol carries out bonding, makes product.

2, the preparation method who is used for the capillary electrophoresis chip of biochemical analysis according to claim 1 is characterized in that: described for the physical dimension of raceway groove is width 10～150 μ m, and the degree of depth 10～80 μ m, length is 30～300mm.

3, according to claim 1, the 2 described preparation methods that are used for the capillary electrophoresis chip of biochemical analysis, it is characterized in that: the time that described grafting is handled is 10 minutes.

4, according to claim 1, the 2 described preparation methods that are used for the capillary electrophoresis chip of biochemical analysis, it is characterized in that: the time that described modification is handled is 15 minutes.

5, the preparation method who is used for the capillary electrophoresis chip of biochemical analysis according to claim 3 is characterized in that: the time that described modification is handled is 15 minutes.

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