Microplastic identification device based on microfluidic and fluorescence technology

Abstract

The utility model mainly relates to the technical field of micro-plastic identification, in particular to a micro-plastic identification device based on microfluidics and fluorescence technology, which comprises a device body, a filter chamber, a reaction chamber, a dyeing chamber and a detection chamber are sequentially arranged on the device body, the filter chamber, the reaction chamber, the dyeing chamber and the detection chamber are sequentially communicated, and the reaction chamber, the dyeing chamber and the detection chamber are sequentially communicated. The micro-plastic samples are sequentially distributed at intervals along the flowing direction of the micro-plastic samples; a filtering unit is arranged in the filtering chamber and is used for filtering the micro-plastic sample; the reaction chamber is filled with a digesting agent, and the digesting agent is used for decomposing organic substances in the micro-plastic sample; the dyeing chamber is filled with a fluorescent agent; a color developing device is arranged in the detection chamber and is used for exciting fluorescence of the micro-plastic sample. According to the micro-plastic identification device, high-sensitivity identification of micro-plastic is realized, the identification accuracy is improved, and the false detection rate is reduced to a greater extent.

Description

Technical Field

[0001] The utility model mainly relates to the technical field of microplastic identification, and in particular to a microplastic identification device based on microfluidics and fluorescence technology. Background Art

[0002] At present, microplastic pollution has become a global environmental problem. The presence of microplastics has brought many negative impacts on the environment and ecosystem, such as toxicity to aquatic organisms, pollution of the food chain, and destruction of ecosystem functions. Therefore, the monitoring, identification and treatment of microplastics have become one of the important issues in environmental protection and sustainable development. Traditional microplastic detection methods such as Fourier transform infrared spectroscopy and mass spectrometry usually require a lot of time and resources, and are complicated to operate, and are not suitable for rapid on-site detection.

[0003] Microfluidics technology can reduce the complex processes and instruments in traditional laboratories to the micron level, realizing the miniaturization and integration of laboratory functions. Its rapid responsiveness enables sample processing and analysis to be completed in a shorter time, and it can greatly reduce the consumption of reagents and samples, making it economical and practical.

[0004] Fluorescence detection technology has good prospects in identifying microplastic pollutants. Its advantages include high sensitivity and selectivity, and it can accurately distinguish microplastic particles. It is also suitable for the detection of different environmental samples and has a wide range of applications. However, fluorescence detection also has some disadvantages. For example, most methods require labeling or processing of samples, which increases the experimental steps and complexity; it may be interfered by other substances in the environment, affecting the accuracy of the test results; some fluorescent probes or markers are only suitable for specific types of microplastics, so there is a problem of limited detection range. Utility Model Content

[0005] In view of this, the utility model provides a microplastic identification device based on microfluidics and fluorescence technology.

[0006] A microplastic identification device based on microfluidics and fluorescence technology comprises a device body, on which a filtration chamber, a reaction chamber, a staining chamber and a detection chamber are sequentially arranged, wherein the filtration chamber, the reaction chamber, the staining chamber and the detection chamber are sequentially connected and sequentially spaced and distributed along the flow direction of the microplastic sample; a filtration unit is arranged inside the filtration chamber, and the filtration unit is used to filter the microplastic sample; the reaction chamber is filled with a digester, and the digester is used to decompose organic matter in the microplastic sample; the staining chamber is filled with a fluorescent agent; and a color developing device is arranged in the detection chamber, and the color developing device is used to excite the fluorescence of the microplastic sample.

[0007] Furthermore, it also includes a first pumping unit, a second pumping unit and a third pumping unit. The first pumping unit is connected to the filtration chamber and is used to pump microplastic samples into the filtration chamber. The second pumping unit is connected to the reaction chamber and is used to pump digesters into the reaction chamber. The third pumping unit is connected to the staining chamber and is used to pump fluorescent agents into the staining chamber.

[0008] Further, the first pumping unit, the second pumping unit and the third pumping unit are respectively a first microfluidic pump, a second microfluidic pump and a third microfluidic pump.

[0009] Furthermore, the filtration unit is a polytetrafluoroethylene filter membrane, which is arranged in the filtration chamber in a direction perpendicular to the flow direction of the microplastic sample and is connected and fixed to the corresponding side wall of the filtration chamber.

[0010] Furthermore, the color development device includes a power generation unit and two electrode sheets. The detection chamber is divided into a first chamber and a second chamber independently arranged up and down by a partition. The second chamber is connected and communicated with the staining chamber. The power generation unit is arranged in the second chamber. The first chamber is filled with xenon gas. Two electrode sheets are arranged in the first chamber and are electrically connected to the power generation unit. The partition is a glass plate.

[0011] Furthermore, the electrode sheet is a copper foil electrode.

[0012] Furthermore, the power generation unit includes a plurality of friction rods, each of which is a cylindrical structure, is vertically arranged and evenly distributed on the bottom wall of the second chamber, and a friction power generation layer is provided on the surface of each of the friction rods.

[0013] Furthermore, the friction power generation layer is a fluorinated ethylene propylene film layer.

[0014] Furthermore, the filtration chamber, the reaction chamber, the staining chamber and the detection chamber are all connected by pipelines, and a first piston valve is provided on the pipeline connecting the filtration chamber and the reaction chamber, a second piston valve is provided on the pipeline connecting the reaction chamber and the staining chamber, and a third piston valve is provided on the pipeline connecting the staining chamber and the detection chamber.

[0015] The beneficial effects brought by the technical solution provided by the utility model are:

[0016] (1) The utility model is a microplastic identification device based on microfluidics and fluorescence technology. Microfluidics can achieve high-sensitivity detection of microplastics through microfluid manipulation in microchannels, ensuring high precision while maintaining high sensitivity. At the same time, microfluidics can realize a miniaturized and integrated detection system, integrating multiple steps such as sample processing, impurity degradation, staining, and detection into one device, reducing experimental operation steps, sample usage, and contamination risks.

[0017] (2) The utility model is a microplastic identification device based on microfluidics and fluorescence technology, which combines fluorescence technology and utilizes the principles of fluorescence staining and luminescence to achieve high-sensitivity identification of microplastics. The detection accuracy can reach 85%, which improves the identification accuracy and greatly reduces the false detection rate.

[0018] (3) The utility model is a microplastic identification device based on microfluidics and fluorescence technology, which utilizes nano-friction power generation technology. Nano-friction power generation technology has the characteristics of small size, low cost, and sustainability. It can achieve self-sufficiency of the equipment and generate electricity using tiny mechanical movements. It does not require an external power supply, thus saving energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a microplastic identification device based on microfluidics and fluorescence technology described in the utility model;

[0020] Figure 2 It is a structural schematic diagram of a microplastic identification device based on microfluidics and fluorescence technology described in the utility model;

[0021] Figure 3 It is a structural schematic diagram of the detection chamber of the utility model. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model clearer, the implementation mode of the utility model will be further described below in conjunction with the accompanying drawings.

[0023] Please refer to Figure 1-3 The embodiment of the utility model provides a microplastic identification device based on microfluidics and fluorescence technology, comprising a device body 100, on which a filtration chamber 10, a reaction chamber 20, a dyeing chamber 30 and a detection chamber 40 are sequentially arranged, and the filtration chamber 10, the reaction chamber 20, the dyeing chamber 30 and the detection chamber 40 are sequentially connected and sequentially spaced and distributed along the flow direction of the microplastic sample;

[0024] The filter chamber 10 is provided with a filter unit 11, and the filter unit 11 is used to filter the microplastic sample;

[0025] The reaction chamber 20 is filled with a digester, which is used to decompose organic matter in the microplastic sample;

[0026] The dyeing chamber 30 is filled with a fluorescent agent;

[0027] The detection chamber 40 is provided with a color developing device, which is used to excite the fluorescence of the microplastic sample.

[0028] In the above embodiment, the device body 100 is a rectangular parallelepiped structure, and the filter chamber 10, the reaction chamber 20, the staining chamber 30 and the detection chamber 40 are spaced apart along the length direction of the device body 100, and as an embodiment of the utility model, the filter chamber 10 is designed as a rectangular chamber of 10 cm long and 10 cm wide, the reaction chamber 20 is a rectangular chamber of 15 cm long and 10 cm wide, and the staining chamber 30 is a rectangular chamber of 10 cm long and 5 cm wide. The filter chamber 10 is the main container for storing microplastic samples, and the reaction chamber 20 is a place for chemical treatment of microplastics. A specific chemical digester is used to digest the organic matter and pollutants that may exist on the surface of the microplastics, so that the surface is suitable for staining treatment, so as to facilitate subsequent analysis and identification. The staining chamber 30 is designed to achieve effective staining of microplastic samples. Optimally, an automatic temperature control system is provided in the dyeing chamber 30 for adjusting the temperature of the reaction environment to optimize the dyeing effect. It should be noted that the automatic temperature control system of the present invention is a prior art, and any intelligent system in the prior art that can automatically control the temperature of the dye can be used as a specific embodiment of the automatic temperature control system of the present invention.

[0029] The filtration chamber 10, the reaction chamber 20, the staining chamber 30 and the detection chamber 40 are all connected by pipelines, and a first piston valve 12 is provided on the pipeline connecting the filtration chamber 10 and the reaction chamber 20, a second piston valve 21 is provided on the pipeline connecting the reaction chamber 20 and the staining chamber 30, and a third piston valve 31 is provided on the pipeline connecting the staining chamber 30 and the detection chamber 40.

[0030] The first piston valve 12, the second piston valve 21 and the third piston valve 31 are all made of hard alloy. The first piston valve 12, the second piston valve 21 and the third piston valve 31 are not affected by moisture and remain stable in a high-pressure environment. The flow rate can be accurately controlled at 0.05L / h~1.5L / h, and the pressure can be controlled between 0.1MPa~1MPa. The first piston valve 12, the second piston valve 21 and the third piston valve 31 are all automatic valves. The main function of the first piston valve 12 is to regulate the flow rate and pressure of water to ensure the stability of the water flow. The second piston valve 21 is located on the sample transmission path, connecting the digester reaction chamber 20 and the fluorescent staining chamber 30. Its function is to further adjust the flow rate and pressure of the water sample containing microplastics, ensure the uniformity of the flow rate and the stability of the pressure during the transportation of the water sample, and fully reflect the digester, thereby optimizing the pretreatment effect. Similarly, the third piston valve 31 can ensure the stable flow of microplastic samples.

[0031] In the utility model, the digester can effectively remove organic impurities in the microplastic sample and reduce interference in the analysis process. Digester treatment is a key link in optimizing the microplastic sample processing. Through the precisely controlled digester and the microplastic sample, the organic matter or pollutants on the surface of the microplastic are effectively treated and prepared for subsequent staining or further analysis.

[0032] In the present invention, the fluorescent agent selected is Nile red, and the most suitable staining concentration is 10 μg / mL. The hydrophobic nature of the Nile red molecule makes it tend to bind to the hydrophobic area on the surface of microplastics. Microplastics are usually composed of polymers such as polyethylene, polypropylene, etc., and the surfaces of these substances are highly hydrophobic. After Nile red is bound to microplastics, its fluorescence performance will be enhanced due to the hydrophobicity of the environment, that is, the fluorescence intensity is higher in a hydrophobic environment. The treated microplastics react with the Nile red dye in this module to form a fluorescent marker, which is then moved to the detection chamber 40 for identification. The excitation wavelength of the fluorescent agent of the present invention is about 500nm, and it has a strong emission intensity.

[0033] The recognition principle of the recognition device described in the utility model is as follows: after the microplastic sample enters the filtering chamber 10, the large particles and other impurities in the microplastic sample are filtered out by the filtering unit 11, and the filtered microplastic sample flows into the reaction chamber 20. After the digester degrades the microplastic sample, the microplastic sample flows into the staining chamber 30. The microplastic sample reacts with the fluorescent agent in the staining chamber 30, and the microplastics in the microplastic sample are fluorescently marked under the action of the fluorescent agent. Then, the microplastic sample flows into the detection chamber 40, and the fluorescence on the microplastics in the microplastic sample is excited by the color development device, and then the microplastics in the microplastic sample are identified using fluorescence technology.

[0034] Furthermore, it also includes a first pump unit 13, a second pump unit 22 and a third pump unit 32. The first pump unit 13 is connected to the filter chamber 10, and is used to pump microplastic samples into the filter chamber 10. The second pump unit 22 is connected to the reaction chamber 20, and is used to pump digesters into the reaction chamber 20. The third pump unit 32 is connected to the staining chamber 30, and is used to pump fluorescent agents into the staining chamber 30.

[0035] Furthermore, the first pumping unit 13 includes a first micro-fluidic pump, and the first micro-fluidic pump is connected and communicated with the liquid inlet of the filter chamber 10 through a pipeline.

[0036] As an embodiment of the utility model, the length and width of the microchannel in the first microfluidic pump are both 200μm, the length is 50mm, and the adjustable flow rate range is 3μL / min to 300μL / min. The first microfluidic pump can achieve accurate, trace, uniform and continuous output of microplastic samples, ensuring the accuracy of the flow rate of microplastic samples. In addition, the first microfluidic pump can accurately control the rate at which microplastic samples pass through the filter unit 11, which is the key to ensuring efficient microplastic collection. In different preset time periods, the first microfluidic pump adjusts the flow rate and pressure as needed to accurately control the amount of water in the filter chamber 10 to meet different sampling requirements.

[0037] Furthermore, the filtration unit 11 is a polytetrafluoroethylene filter membrane, which is arranged in the filtration chamber 10 in a direction perpendicular to the flow direction of the microplastic sample, and is connected and fixed to the corresponding side wall of the filtration chamber 10.

[0038] In the present invention, the filter unit 11 is arranged in the filter chamber 10 along the vertical direction, and is detachably connected to the corresponding side wall of the filter chamber 10 to facilitate the replacement of the filter unit 11. The detachable connection structure between the filter unit 11 and the filter chamber 10 in the present invention can be a connection structure of a slide groove and a slider. Specifically, the filter unit 11 is a polytetrafluoroethylene filter membrane with a pore size of 0.2μm. The polytetrafluoroethylene filter membrane can remove large particle pollutants and impurities that affect detection, prevent pipeline blockage, and the polytetrafluoroethylene filter membrane has a fast filtering efficiency and a good filtering effect to adapt to different test conditions and requirements.

[0039] In the above embodiment, the second pumping unit 22 is a second microfluidic pump, and the second microfluidic pump is connected and communicated with the liquid inlet of the reaction chamber 20 through a pipeline.

[0040] As an embodiment of the present invention, the main task of the second microfluidic pump is to accurately control the flow rate and pressure of the pumped digester. By adjusting the parameters, the dosage of the digester can be accurately controlled.

[0041] In the above embodiment, the digester is a composite solvent, and the digestion solution prepared by taking a certain potassium hydroxide solution, potassium permanganate solution, surfactant hexadecyltrimethylammonium bromide and complexing agent ethylenediaminetetraacetic acid dimethyl salt can effectively destroy organic matter and convert it into small molecules such as CO and water, thereby removing organic impurities in microplastic samples and reducing interference in the analysis process. The dosage ratio of the digester to the microplastic sample to be tested is about 3:1. The effect of the digester is about 40% higher than that of ordinary digesters such as nitric acid, potassium hydroxide, hydrogen peroxide, etc., and the digestion rate can reach 90%. After digestion, the microplastics are released and flow to the dyeing module through the micro-channel.

[0042] In the above embodiment, the third pumping unit 32 is a third microfluidic pump, and the second microfluidic pump is connected and communicated with the liquid inlet of the dyeing chamber 30 through a pipeline.

[0043] In the present invention, the fluorescent agent is injected through the third microfluidic pump, and the fluorescent agent reacts with the microplastic sample in the staining chamber 30 to form a stable fluorescent marker. The third microfluidic pump can ensure the accurate delivery of the fluorescent dye and improve the uniform staining of the microplastic sample.

[0044] In the above embodiment, the color development device includes a power generation unit and two electrode sheets 41. The detection chamber 40 is divided into a first chamber 43 and a second chamber 44 independently arranged up and down by a partition. The second chamber 44 is connected and communicated with the dyeing chamber 30. The power generation unit is arranged in the second chamber 44. The first chamber 43 is filled with xenon gas. The two electrode sheets 41 are both arranged in the first chamber 43 and are both electrically connected to the power generation unit. The partition is a glass plate.

[0045] As an embodiment of the present invention, the detection chamber 40 is a rectangular structure, and the first chamber 43 is 5 cm long and 3 cm wide. The electrode sheet 41 is a copper foil electrode, which has a low production cost and can generate a voltage of up to 3V, which can provide xenon gas with light.

[0046] The working principle of the color development device is to transmit voltage to the two electrode sheets 41 through the power generation unit. Under the action of the voltage, the xenon gas emits light, and the emitted light source illuminates the microplastic sample through the partition to stimulate the fluorescence on the microplastics in the microplastic sample. The purpose of detection can be achieved directly through visual fluorescence. In addition, the fluorescence signal can be collected and further analyzed by optical detection equipment, such as a CCD camera or a CMOS sensor, so as to realize the identification of microplastics.

[0047] In the above embodiment, the power generation unit includes a plurality of friction rods 42, each of which is a cylindrical structure. The friction rods 42 are vertically arranged and evenly distributed on the bottom wall of the second chamber 44, and a friction power generation layer is provided on the surface of each friction rod 42.

[0048] In the present invention, the friction power generation layer is a fluorinated ethylene propylene film with a thickness of 20 to 30 microns. A plurality of friction rods 42 form an array electrode. When the microplastic sample passes through the array electrode, liquid-solid friction power generation forms a phase difference, and the generated voltage can reach 3V, which can be used for xenon light emission. In the present invention, power generation is achieved by means of the principle of nano friction power generation technology. Nano friction power generation technology has the characteristics of small size, low cost, and sustainability. It can achieve self-sufficiency of the equipment, generate electricity by using tiny mechanical movements, and does not require an external power supply, thus saving energy consumption.

[0049] In addition, the utility model also provides a method for detecting microplastics in water samples using the above-mentioned identification device, comprising the following steps:

[0050] 1) Introduce the water sample into the filter chamber 10 through the first micro flow pump. After starting the first micro flow pump, adjust the flow rate of the water sample through the polytetrafluoroethylene filter membrane by setting the flow rate and pressure of the water sample.

[0051] 2) The filtered water sample is transferred to the reaction chamber 20 through the first piston valve 12, and the second micro-flow pump is turned on, and then a preset amount of digester is slowly added. The digester reacts with the microplastics under controlled conditions to prepare for dyeing.

[0052] 3) The pretreated water sample enters the staining chamber 30 through the second piston valve 21, and the second microfluidic pump is turned on to inject Nile red dye, and the flow and pressure of the fluorescent dye to the fluorescent staining chamber 30 are precisely controlled. In the fluorescent staining chamber 30, the fluorescent dye reacts with the microplastics to form a stable fluorescent marker, which is ready for recognition by the color development module.

[0053] 4) The dyed water sample passes through the third piston valve 31 and enters the second chamber 44. The flow rate is adjusted, and the fluid friction array generates electric charge to form a potential difference. The current is output through the two electrode sheets 41 to light up the xenon gas. The fluorescent dye emits fluorescence under light of a specific wavelength, and the fluorescent signal emitted from the microplastic particles is collected;

[0054] 5) Going further, optical detection equipment can be used to capture fluorescent signals and process the data through analysis software to ultimately output analysis results on the type and quantity of microplastics.

[0055] 6) Repeat the above steps.

[0056] In this document, the directional words such as front, back, top, and bottom are defined by the positions of the components in the drawings and the positions of the components relative to each other, and are only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application.

[0057] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A microplastic identification device based on microfluidics and fluorescence technology, characterized in that: The device comprises a main body, on which a filtration chamber, a reaction chamber, a staining chamber and a detection chamber are sequentially arranged, wherein the filtration chamber, the reaction chamber, the staining chamber and the detection chamber are sequentially connected and sequentially spaced apart along the flow direction of the microplastic sample; a filtration unit is arranged inside the filtration chamber, and the filtration unit is used for filtering the microplastic sample; the reaction chamber is filled with a digester, and the digester is used for decomposing organic matter in the microplastic sample; the staining chamber is filled with a fluorescent agent; and a color developing device is arranged in the detection chamber, and the color developing device is used for exciting the fluorescence of the microplastic sample.

2. According to claim 1, a microplastic identification device based on microfluidics and fluorescence technology is characterized in that: It also includes a first pumping unit, a second pumping unit and a third pumping unit. The first pumping unit is connected to the filtration chamber, and is used to pump microplastic samples into the filtration chamber. The second pumping unit is connected to the reaction chamber, and is used to pump digestion agents into the reaction chamber. The third pumping unit is connected to the staining chamber, and is used to pump fluorescent agents into the staining chamber.

3. A microplastic identification device based on microfluidics and fluorescence technology according to claim 2, characterized in that: The first pumping unit, the second pumping unit and the third pumping unit are respectively a first microfluidic pump, a second microfluidic pump and a third microfluidic pump.

4. The microplastic identification device based on microfluidics and fluorescence technology according to claim 1, characterized in that: The filtration unit is a polytetrafluoroethylene filter membrane, which is arranged in the filtration chamber in a direction perpendicular to the flow direction of the microplastic sample and is connected and fixed to the corresponding side wall of the filtration chamber.

5. The microplastic identification device based on microfluidics and fluorescence technology according to claim 1, characterized in that: The color development device includes a power generation unit and two electrode sheets. The detection chamber is divided into a first chamber and a second chamber independently arranged up and down by a partition. The second chamber is connected to and communicated with the staining chamber. The power generation unit is arranged in the second chamber. The first chamber is filled with xenon gas. Two electrode sheets are arranged in the first chamber and are electrically connected to the power generation unit. The partition is a glass plate.

6. The microplastic identification device based on microfluidics and fluorescence technology according to claim 5, characterized in that: The electrode sheet is a copper foil electrode.

7. The microplastic identification device based on microfluidics and fluorescence technology according to claim 5, characterized in that: The power generation unit comprises a plurality of friction rods, each of which is a cylindrical structure, is vertically arranged and evenly distributed on the bottom wall of the second chamber, and a friction power generation layer is provided on the surface of each of the friction rods.

8. The microplastic identification device based on microfluidics and fluorescence technology according to claim 7, characterized in that: The friction power generation layer is a fluorinated ethylene propylene film layer.

9. The microplastic identification device based on microfluidics and fluorescence technology according to claim 1, characterized in that: The filtration chamber, the reaction chamber, the staining chamber and the detection chamber are all connected by pipelines, and a first piston valve is provided on the pipeline connecting the filtration chamber and the reaction chamber, a second piston valve is provided on the pipeline connecting the reaction chamber and the staining chamber, and a third piston valve is provided on the pipeline connecting the staining chamber and the detection chamber.

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