CN104888874B - Preparation method and application of micro-fluidic chip based on 3D printing technique - Google Patents

Abstract

The invention provides a method for preparing a microfluidic chip based on 3D printing technology and its application; method steps: 1. Design a microfluidic pipeline, and print a filament by a 3D desktop printer, and the filament material used is acrylonitrile- Butadiene-styrene copolymer, polylactic acid resin, and polyvinyl alcohol are used as channel templates for microfluidic chips; second, transfer the printed filaments to a watch glass, and fix the filaments on the substrate. , and then pouring PDMS colloid, curing, demoulding, punching, and bonding to prepare a microfluidic chip. The present invention also relates to the application of the above-mentioned microfluidic chip in surface-enhanced Raman Raman detection. The invention has simple preparation, fast processing, very low cost, and does not need complex micro-processing such as photolithography, development and other processes, and can also complete the preparation of the microfluidic chip under common experimental conditions. The preparation of the microfluidic chip is easy to popularize, and can be widely used in the fields of human health, food safety, environmental detection, medical diagnosis and the like.

Description

Preparation method and application of microfluidic chip based on 3D printing technology

technical field

The invention relates to a preparation method of a microfluidic chip, in particular to a rapid preparation method of a microfluidic chip based on desktop 3D printing technology and its application.

Background technique

The microfluidic system is a process of manipulating a small volume of liquid (10 ^-9 –10 ^-18 L) in a pipeline of tens to hundreds of microns. This technology has a very broad application prospect in biomedicine, environmental monitoring, and food safety. Microfluidic devices have the following advantages, such as small size, reduced reagent consumption, and parallel detection of multiple samples. However, the preparation of traditional microfluidic chips requires complex processes such as mask plate preparation, glue removal, photolithography, and development. The preparation process is complex, the preparation cycle is long, the cost is high, and the processing technology is high. Finish.

Contents of the invention

In view of the defects in the prior art, the object of the present invention is to provide a preparation method of a microfluidic chip based on 3D printing technology and its application.

The present invention is achieved through the following technical solutions:

In a first aspect, the present invention relates to a method for preparing a microfluidic chip based on 3D printing technology, the method comprising the following steps:

Step 1, use 3D drawing software to design the microfluidic pipeline, and print the filaments through a 3D desktop printer as a channel template for the microfluidic chip;

Step 2: transfer the printed filaments to a watch glass, fix the filaments on the substrate, and then pour the PDMS colloid after being fixed, solidify, demould, punch holes, and bond to prepare a microfluidic chip.

Preferably, the 3D desktop printer is a fused deposition printer.

Preferably, the filament is made of acrylonitrile-butadiene-styrene copolymer or polylactic acid resin.

Preferably, the diameter of the filament is 0.1-1 mm.

Preferably, in step 2, the fixing of the filaments on the substrate refers to: using PDMS colloid to fix or take a small amount of filaments and place them close to the substrate.

Preferably, in step 2, when pouring the PDMS colloid, the filaments need to be completely fixed to the substrate before pouring.

In the second aspect, the present invention also relates to the application of the microfluidic chip prepared by the aforementioned method, and the microfluidic chip prepared based on 3D printing technology is applied to surface-enhanced Raman Raman detection in melamine.

Preferably, the application of the microfluidic chip in surface-enhanced Raman detection specifically includes the following steps:

The first step is to prepare a microfluidic chip using the above-mentioned 3D printing process, and design a small cuboid in the middle of the pipeline;

The second step is to prepare a porous monolithic column on the small cuboid part of the microfluidic chip;

The third step is to fix the silver microspheres in the pipeline of the microfluidic chip, and use the porous monolithic column prepared in the pipeline to physically block the silver microspheres, so as to realize the immobilization of the silver microspheres in front of the monolithic column of the microfluidic chip;

The fourth step is to use the microfluidic chip containing immobilized silver microspheres obtained in the third step above to detect melamine surface-enhanced Raman: use a syringe pump to inject the sample solution containing melamine into the microfluidic chip at 2-20 μL/min, The melamine in the sample is enriched by using the adsorption of melamine by the silver microspheres in the chip, and finally, the Raman detection of the melamine adsorbed on the silver microspheres is carried out by using surface-enhanced Raman.

Preferably, the second step, specific steps:

Step 1, prepare the monolithic column solution: use glycidyl methacrylate, ethylene glycol dimethacrylate, and di-n-octyl phthalate, mix according to the weight ratio of 2:3:5, and then add the total weight of the mixture 5 % photoinitiator dimethylolpropionic acid, ultrasonically mixed, placed in a refrigerator at 4°C for storage;

Step 2, injecting the whole column solution into the pipeline of the microfluidic chip with a pipette gun, and filling the pipeline of the whole microfluidic chip;

Step 3, using an ultraviolet point light source to expose the small cuboid of the microfluidic chip injected with the monolithic column solution for 60 seconds, and the exposed area of the monolithic column solution is cured and integrated with the pipeline of the microfluidic chip;

Step 4, respectively use methanol, acetone and water to wash at 2-50 μL/min for 10-30 min through a syringe pump to remove the unreacted monolithic column solution and wash away the di-n-octyl phthalate in the solidified monolithic column, namely A microfluidic chip with a porous monolithic column is obtained, and the obtained monolithic column is a porous structure with a pore size within 1 μm.

Preferably, the third step is specifically: the size of the silver microspheres used is 1-2 μm, injecting 5 μL of silver microspheres dispersed in methanol into the microfluidic chip pipeline, using methanol at a flow rate of 10-50 μL/min Inject into microfluidic chip channels.

The above-mentioned chip of the present invention can be applied to the detection fields of medical diagnosis, environmental monitoring, food safety, etc., such as detection of melamine in food, pesticides, heavy metals in water environment, clinical biological samples, detection of pathogenic bacteria, etc.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention uses desktop 3D printing filaments as microfluidic chip channels, and then pours PDMS to prepare microfluidic chips. This method is very simple, convenient, and low in preparation cost. It can be completed under general laboratory conditions, and It is applied to surface-enhanced Raman detection.

(2) The preparation and processing of the present invention are convenient, without the need to adopt complex process equipment, and save a large amount of cumbersome micro-processing techniques; the design is more flexible, and the production and preparation cycle is significantly shortened; it can be mass-produced quickly, with extremely low cost and less consumable materials; easy to operate , non-professionals can also quickly master.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is the effect diagram of microfluidic pipeline design using 3D-max drawing software in Embodiment 1 of the present invention;

Fig. 2 is the immobilization picture of the filament prepared based on 3D printing in Example 1 of the present invention on the watch glass substrate;

Fig. 3 is a schematic structural diagram of a microfluidic chip prepared by 3D printing technology in the present invention;

FIG. 4 is a physical diagram of a microfluidic chip prepared by 3D printing technology in Example 1 of the present invention;

5 is a photomicrograph of silver microspheres fixed on a microfluidic monolithic column chip in Example 1 of the present invention;

Fig. 6 is the detection result of dimercaptopyridine Raman signal in embodiment 1 of the present invention;

Fig. 7 is the result of detecting melamine in the microfluidic monolithic column using surface-enhanced Raman detection in Example 1 of the present invention.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example 1

This embodiment relates to a method for preparing a microfluidic chip based on 3D printing technology, the method comprising the following steps:

Step 1: Use 3D drawing software to design the microfluidic pipeline. The pipeline design is shown in Figure 1. Use fused deposition to 3D print out the microfluidic channel lines. The diameter of the lines ranges from 0.5 to 1mm. Cut into chip channels;

Step 2, then transfer to a watch glass, pass a little PDMS colloid, fix it on the substrate, as shown in Figure 2, pour PDMS colloid in a watch glass, place in an 80-degree oven for 2 hours, solidify and demould, punch holes and bond, and prepare microfluidics control chip;

The application of the microfluidic chip prepared above in surface-enhanced Raman detection specifically includes the following steps:

In the first step, the schematic diagram of the result of the microfluidic chip prepared based on 3D printing is shown in Figure 3. The design shape of the microfluidic chip is shown in Figure 1. The length x width x height of the chip pipeline = 15mmx0.4x0.3mm, in the middle of the pipeline Design a small cuboid, its size length x width x height = 1x0.8x0.3mm;

The second step is to prepare a porous monolithic column on the small cuboid part of the microfluidic chip. The specific steps are:

1. Prepare the monolithic column solution, use glycidyl methacrylate, ethylene glycol dimethacrylate, and di-n-octyl phthalate, mix according to the weight ratio of 2:3:5, and then add 5% of its total weight The photoinitiator dimethylolpropionic acid was mixed ultrasonically and stored in a refrigerator at 4°C;

2. Inject the monolithic column solution into the microfluidic chip pipeline with a pipette gun, and fill the whole microfluidic chip pipeline;

3. Use an ultraviolet point light source to expose the small cuboid of the microfluidic chip after injecting the monolithic column solution for 60 seconds, and the exposed area of the monolithic column solution is cured and integrated with the microfluidic chip pipeline;

4. Use methanol, acetone, and water to wash at 2-50 μL/min for 10-30 min through a syringe pump to remove the monolithic column solution that did not participate in the reaction and wash away the di-n-octyl phthalate in the solidified monolithic column, that is A microfluidic chip with a porous monolithic column is obtained, and the monolithic column obtained is a porous structure with a pore size within 1 μm. As shown in Figure 4.

The third step is to immobilize silver microspheres in the pipeline of the microfluidic chip: the size of the silver microspheres used is 1-2um, and 5uL of silver microspheres dispersed in methanol are injected into the pipeline of the microfluidic chip, and methanol is used to dissolve the silver microspheres in 10- The flow rate of 50ul/min is injected into the microfluidic chip channel, and the silver microspheres are fixed in front of the microfluidic chip monolithic column by using the porous monolithic column prepared in the pipeline to physically block the silver microspheres. As shown in Figure 5.

In the fourth step, a microfluidic chip containing immobilized silver microspheres is used to perform surface-enhanced Raman detection on enriched 2-mercaptopyridine Raman molecules of different volumes. In specific steps, a syringe pump is used to inject the 0.1 μmol/L Raman molecule 2-mercaptopyridine solution into the microfluidic monolithic column chip containing silver microspheres at a flow rate of 2-10 μL/min, and inject different sample volumes ( 1ul, 8ul, 12ul, 14ul) after the Raman detection signal collected, as shown in Figure 6.

Example 2

This embodiment relates to a method for preparing a microfluidic chip based on 3D printing technology, the method comprising the following steps:

Step 1: Use 3D drawing software to design microfluidic pipelines, use fused deposition to 3D print microfluidic channel lines, the diameter of the lines ranges from 0.5 to 1mm, and cut the printed lines and filaments into chip channels;

Step 2, then transfer to a watch glass, pass a little PDMS colloid, fix it on the substrate, pour the PDMS colloid in the watch glass, place in a 60°C oven overnight, cure and demould, punch holes and bond, and prepare a microfluidic chip;

The application of the microfluidic chip prepared above in surface-enhanced Raman detection specifically includes the following steps:

In the first step, the monolithic column solution is injected into the microfluidic chip, and a point light source is used to expose the small cuboid area designed by the microfluidic chip to ultraviolet light;

In the second to fourth steps, the monolithic column is washed with methanol, acetone, and water at a flow rate of 10-30 μL/min to prepare a microfluidic monolithic column chip;

In the fifth step, the silver microspheres dispersed in methanol are injected into the microfluidic monolithic column washing sheet, and the silver microspheres are fixed by the monolithic column blocking;

Step 6: Inject 0.1 mg/L melamine solution into the microfluidic monolithic column chip containing silver microspheres at a flow rate of 2-10 μL/min. After 10 min, collect surface-enhanced Raman detection, and the results are shown in Figure 7 shown.

Example 3

This embodiment relates to a method for preparing a microfluidic chip based on 3D printing technology, the method comprising the following steps:

Step 1: Use 3D drawing software to design microfluidic pipelines, use fused deposition to 3D print microfluidic channel lines, the diameter of the lines ranges from 0.1 to 1mm, and cut the printed lines and filaments into chip channels;

Step 2, then transfer to a watch glass, apply a small amount of 502 glue on the line, fix it to the substrate, pour PDMS colloid in the watch glass, place it in a 60°C oven for 6 hours, cure and demould, punch holes and bond, and prepare micro Fluidic chip, the schematic diagram of the microfluidic chip prepared based on 3D printing is shown in Figure 3.

The application of the microfluidic chip prepared above includes the following steps:

In the first step, the monolithic column solution is injected into the microfluidic chip, and a point light source is used to expose the small cuboid area to ultraviolet light;

In the second step, the monolithic column is washed with methanol, acetone, and water at a flow rate of 10-30 μL/min to prepare a microfluidic monolithic column chip;

In the third step, the magnetic beads are injected into the microfluidic monolithic column washing slice, and the magnetic beads are fixed by the monolithic column blocking;

The fourth step is to inject 0.01 mg/L melamine solution into the microfluidic chip at a flow rate of 5 μL/min for 30 min enrichment;

In the fifth step, surface-enhanced Raman is used to detect the melamine enriched on the surface of the silver microspheres, and the parallel test is performed 3 times.

The microfluidic chip method prepared by the above-mentioned fused deposition 3D printing technology of the present invention is simple to prepare, fast to process, very low in cost, and does not require complicated micromachining such as photolithography, development and other processes, and can also be used under ordinary experimental conditions Complete the preparation of the microfluidic chip. And the chip is applied to surface-enhanced Raman detection and chemiluminescence detection. The preparation of the microfluidic chip is easy to popularize, and can be widely used in the fields of human health, food safety, environmental detection, medical diagnosis and the like.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (8)

1. a kind of application of micro-fluidic chip is it is characterised in that be applied to the micro-fluidic chip prepared based on 3D printing technique Surface-enhanced Raman detection in tripolycyanamide；

Described micro-fluidic chip is prepared based on 3D printing technique, specifically include following steps：

Step one, using three-dimensional drawing software design Micro-flow pipe, prints filament by 3D desktop printer, as miniflow Control chip channel template；

Step 2, the filament printing is transferred in surface plate, and filament is fixed in substrate, to be fixed after, then pour PDMS colloid, solidification, the demoulding, punching, bonding prepares micro-fluidic chip；

Described micro-fluidic chip detects application in surface-enhanced Raman, specifically includes following steps：

The first step, prepares micro-fluidic chip using above-mentioned 3D printing technique, in the duct between design a little cuboid；

Second step, has cavernous integral post in the little rectangular body region preparation of micro-fluidic chip；

3rd step, carries out silver-colored microsphere in micro-fluidic chip pipeline and fixes, using the cellular integral post prepared in pipeline to silver The physical barriers of microsphere, realize silver-colored microsphere fixing before micro-fluidic chip integral post；

4th step, is strengthened to melamine surface using the micro-fluidic chip containing fixing silver microsphere that above-mentioned 3rd step obtains and draws Graceful detection：Adopt syringe pump will be injected into micro-fluidic chip containing tripolycyanamide sample solution with 2-20 μ L/min, using chip The absorption to tripolycyanamide for the microsphere of middle silver, carries out the enrichment to tripolycyanamide in sample, finally, using surface-enhanced Raman to suction The tripolycyanamide being attached on silver-colored microsphere carries out Raman detection.

2. the application of micro-fluidic chip according to claim 1 is it is characterised in that described second step, concrete steps：

Step 1, prepares integral post solution：Using glycidyl methacrylate, ethylene glycol dimethacrylate, adjacent benzene two Formic acid di-n-octyl, compares 2 according to weight：3：5 mixing, add the light trigger dihydromethyl propionic acid of total weight of the mixture 5%, Ultrasonic mixing, places 4 DEG C of Refrigerator stores；

Step 2, integral post solution is injected in micro-fluidic chip pipeline using liquid-transfering gun, and is full of whole micro-fluidic chip pipe Road；

Step 3, carries out uv-exposure using ultraviolet point source at the little cuboid of micro-fluidic chip after injection integral post solution Time 60s, its integral post solution exposure area solidifies, and integrates one with micro-fluidic chip pipeline；

Step 4, is respectively adopted methanol, acetone and water and passes through syringe pump with 2-50 μ L/min washing 10-30min, removing has neither part nor lot in Phthalic acid di-n-octyl in the integral post solution of reaction and integral post after washing away solidification, that is, obtain with cellular The micro-fluidic chip of integral post, its gained integral post is loose structure, and its pore size is in 1 μm.

3. the application of micro-fluidic chip according to claim 1 and 2 is it is characterised in that described 3rd step, specially：Adopt Silver-colored microsphere size is 1-2 μm, and 5 μ L dispersions silver-colored microsphere in methyl alcohol is injected micro-fluidic chip pipeline, adopt methanol with The flow velocity injection micro-fluidic chip passage of 10-50 μ L/min.

4. the application of micro-fluidic chip according to claim 1 and 2 is it is characterised in that described 3D desktop printer is to adopt With fusion sediment type printer.

5. the application of micro-fluidic chip according to claim 1 and 2 is it is characterised in that the material of described filament is propylene Nitrile-BS or polylactic resin.

6. the application of micro-fluidic chip according to claim 1 and 2 is it is characterised in that a diameter of 0.1- of described filament 1mm.

7. the application of micro-fluidic chip according to claim 1 and 2 is it is characterised in that in step 2, described solid by filament Determine to refer to in substrate：Fix using PDMS colloid or take micro filament to be close to substrate to place.

8. the application of micro-fluidic chip according to claim 1 and 2 is it is characterised in that in step 2, pour PDMS colloid When, filament is poured after needing to be completely fixed with substrate.