Environmental pollutant detection device, preparation method and use method thereof

Abstract

The invention relates to the technical field of microfluidics, in particular to an environmental pollutant detection device, a preparation method and a use method thereof, and the preparation method comprises the following steps: selecting a glass substrate; printing a nanopore film sensor array, a first inlet unit, a first capillary array, a blocking unit and an outflow unit; and functionalizing the nanopore film sensor array to obtain a detection unit. The use method comprises the following steps: fully reacting a sample to be detected at the detection unit; the broadband light source is used for irradiating the detection unit, the reflected light signal deviates, and whether the sample contains the target heavy metal ions or not can be determined according to the light signal deviation result. The device comprises a glass substrate, and a first inlet unit, a first capillary tube array, a detection unit, a blocking unit and a second capillary tube array which are sequentially arranged on the glass substrate in a communicating manner. According to the invention, environmental pollutant detection can be rapidly realized, and the system has good reusability and portability and wide application scenarios.

Description

Technical Field

[0001] The present invention relates to the technical field of microfluidics, and more specifically, to an environmental pollutant detection device, a preparation method and a use method thereof. Background Art

[0002] Among industrial pollution, oil wastewater produced by oil companies is particularly serious, and heavy metal ions have become a very important factor in oil wastewater pollution. Heavy metal ions, such as silver and mercury, are highly toxic and difficult to degrade. If they are discharged directly into water or soil without treatment, they may be enriched in organisms and eventually enter the human body through the food chain. Even at very low concentrations, they can cause damage to human organs, such as the brain and lungs, thus becoming a potential threat to public safety.

[0003] In order to reduce the existence of this potential threat, the current detection methods for heavy metal ions in water bodies mainly include: electrochemical analysis, spectroscopy, inductively coupled plasma, colorimetry, etc. However, the electrode preparation and processing steps of electrochemical analysis are relatively complicated, and require precision instruments, which has a high threshold. Although the spectroscopy method has accurate measurement values, its detection instrument is bulky, has high maintenance costs, has high requirements for the detection environment, and cannot achieve real-time monitoring; although the detection of the inductively coupled plasma method has fewer restrictions, its salt tolerance is poor, and some light elements will cause serious interference in the measurement; the colorimetric method has an intuitive measurement process, but its lower limit of measurement is high, and the sensitivity depends significantly on the thickness of the membrane. In addition, the above methods require skilled technicians to operate, and the analysis time is long, which is not suitable for rapid detection in outdoor environments. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of prior art equipment that are not suitable for rapid detection in outdoor environments, and to provide an environmental pollutant detection device, a preparation method and a method of use thereof, which can quickly detect environmental pollutants, have good reusability and portability, and have a wide range of application scenarios.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for preparing an environmental pollutant detection device is provided, comprising the following steps:

[0007] S1. Select a glass substrate;

[0008] S2. Printing a nanopore thin film sensor array on the glass substrate using a photolithography process;

[0009] S3. Printing a first inlet unit and a first capillary array on one side of the nanopore film sensor array by using a photolithography process; wherein the first inlet unit and the nanopore film sensor array are respectively located at the first end and the second end of the first capillary array, and the capillary force direction of the first capillary array is parallel to the extension direction of the first capillary array from the first end to the second end;

[0010] S4. Printing a blocking unit and an outflow unit on the other side of the nanopore film sensor array by using a photolithography process; wherein the blocking unit is located between the nanopore film sensor array and the outflow unit, and the outflow unit includes a second capillary array, a second inlet unit, and an outlet unit, wherein the second inlet unit and the outlet unit are respectively located at the first end and the second end of the second capillary array, and the capillary force direction of the second capillary array is parallel to the extension direction of the second capillary array from the first end to the second end; wherein there is no order between steps S3 and S4;

[0011] S5. Functionalizing the nanopore film sensor array to obtain a detection unit.

[0012] The present invention includes a method for preparing an environmental pollutant detection device. The detection unit is a nanopore film sensor array that is functionalized according to the heavy metal ions in the corresponding environmental pollutants to be detected. It has good specificity, can quickly detect heavy metal ions, and has good reusability. The arrangement of the first capillary array and the second capillary array can guide the rapid flow of liquid, and the amount of liquid lost is extremely small, which can significantly reduce the amount of detection reagent samples and costs. The arrangement of printing each unit on a glass substrate makes the detection device prepared by the preparation method portable, can achieve rapid detection in outdoor environments, and has a wide range of application scenarios.

[0013] Further, step S2 includes the following steps:

[0014] S21. Electroplating titanium on the cleaned glass substrate to obtain a titanium coating;

[0015] S22. Electroplating aluminum on the titanium coating to obtain a first aluminum coating;

[0016] S23. Anodizing the first aluminum coating to obtain an anodized aluminum layer;

[0017] S24. Electroplating aluminum on the anodized aluminum layer to obtain a second aluminum-plated layer;

[0018] S25. Photolithography is performed on the glass substrate after completing step S24, and then the second aluminum coating layer is etched by an etching solution to make the pattern of the nanopore film sensor array appear on the second aluminum coating layer and obtain an array pattern aluminum coating layer;

[0019] S26. The glass substrate after step S25 is immersed in a corrosion solution, so that the pattern of the array pattern aluminum-plated layer appears on the anodized aluminum layer and an array pattern anodized aluminum layer is obtained;

[0020] S27. Etching away the array pattern aluminum-plated layer, and then gold-plating the array pattern anodized aluminum layer to obtain a gold-plated layer to form the nanopore thin film sensor array.

[0021] Furthermore, in step S21, the titanium coating layer is prepared by using an electron beam evaporation coating machine, and the thickness of the titanium coating layer is 5 to 10 nm;

[0022] In step S22, the first aluminum coating layer is prepared by using an electron beam evaporation coating machine, and the thickness of the first aluminum coating layer is 2 to 15 μm;

[0023] In step S23, a DC voltage of 25 to 35 V is applied and the glass substrate after step S22 is placed in an acid solution at 3 to 8° C. for anodization to generate the anodized aluminum layer;

[0024] In step S24, the second aluminum coating layer is prepared by using an electron beam evaporation coating machine, and the thickness of the second aluminum coating layer is 100-200 nm;

[0025] In step S25, the etching solution is a (H3PO4:CH3COOH:HNO3:H2O) solution;

[0026] In step S26, the etching solution is a mixed solution containing 0.4M phosphoric acid and 0.2M chromic acid;

[0027] In step S27, a magnetron sputtering coating machine is used to prepare the gold-plated layer, and the thickness of the gold-plated layer is 5-15 nm.

[0028] Further, step S5 includes the following steps:

[0029] S51. Add 0.1 mM HSC to the nanopore film sensor array under low temperature. 10 COOH and 0.9 mM HSC8OH solution and react, then wash with ethanol solution;

[0030] S52. Adding an activator to the nanopore film sensor array;

[0031] S53. Under low temperature, adding an aptamer corresponding to the sample to be detected to the nanopore film sensor array for reaction;

[0032] S54. adding ethanolamine to the nanopore film sensor array to block the non-occupied sites activated by the activator;

[0033] After each of the above steps is completed, a cleaning step is performed before proceeding to the next step.

[0034] Further, in step S51, a solution is added at 1 to 5°C and reacted for 8 to 12 hours, and then washed with an ethanol solution; in step S52, the activator is added at room temperature and reacted for 1 to 2 hours, and the activator includes NHS and EDC; in step S53, the aptamer is added at 1 to 5°C and reacted for 8 to 12 hours; in step S54, ethanolamine is added at room temperature and reacted for 1 to 2 hours.

[0035] Furthermore, the cleaning step includes: dripping PBS buffer from the first inlet unit, and after the PBS buffer reaches the blocking unit, dripping PBS buffer from the second inlet unit, so that the PBS buffer is discharged from the outlet unit, repeating multiple times to complete the cleaning.

[0036] The present invention also provides a method for using the environmental pollutant detection device prepared by the above preparation method, comprising the following steps:

[0037] I. dripping the sample to be detected from the first inlet unit and flowing to the first capillary array, the sample to be detected spontaneously flows to the detection unit due to the capillary force at the first capillary array and reacts with the aptamer therein, and at this time, the blocking unit can block the sample to be detected at the detection unit for sufficient reaction;

[0038] II. Using a broadband light source to illuminate the surface of the detection unit, the effective refractive index of the nanoporous film will change, and the reflected light signal will shift. According to the shift result of the light signal, it can be determined whether the sample contains target heavy metal ions;

[0039] III. After the detection is completed, buffer solution is continuously added to the second inlet unit, and the buffer solution flows to the second capillary array; when the pressures on both sides of the blocking unit are equal, the blocked sample will flow through the blocking unit to the second capillary array and be discharged through the outlet unit.

[0040] The present invention also provides an environmental pollutant detection device, comprising a glass substrate, on which a first inlet unit, a first capillary array, a detection unit, a blocking unit, and a second capillary array are sequentially connected; the detection unit comprises a functionalized nanopore film sensor array; the capillary force direction of the first capillary array is arranged along the direction from the first inlet unit to the detection unit; a second inlet unit and an outlet unit are respectively arranged at both ends of the second capillary array along the capillary force direction; the capillary force direction of the second capillary array is not parallel to the capillary force direction of the first capillary array.

[0041] Preferably, the blocking unit comprises a plurality of blocking structures arranged in an array, the blocking structure comprising a first protrusion and a second protrusion, a concave position is provided on a side of the first protrusion close to the second capillary array, and the second protrusion is provided at the concave position.

[0042] Preferably, the capillary force direction of the second capillary array is perpendicular to the capillary force direction of the first capillary array; the first capillary array is a micro-rectangular array, in which the micro-rectangular arrays are staggered between columns; the length of the micro-rectangular array is 600-800 μm and the width is 300-500 μm.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The detection unit is a nanopore film sensor array functionalized according to the heavy metal ions in the corresponding environmental pollutants to be detected, and has good specificity and good reusability; the setting of the first capillary array and the second capillary array can guide the rapid flow of liquid, and the amount of liquid lost is extremely small, which can significantly reduce the amount of detection reagent samples and costs; the setting of printing each unit on a glass substrate makes the detection device prepared by the preparation method portable, can realize rapid detection in outdoor environments, and has a wide range of application scenarios; in the method of using the detection device, it can be determined whether the sample contains target heavy metal ions based on the change of the effective refractive index of the nanopore film and the offset result of the optical signal, thereby realizing rapid detection of heavy metal ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of a method for preparing an environmental pollutant detection device according to the present invention;

[0046] Figure 2 This is a flow chart of step S2 of the preparation method of the present invention;

[0047] Figure 3It is a structural schematic diagram of a first embodiment of an environmental pollutant detection device of the present invention;

[0048] Figure 4 It is a structural schematic diagram of a second embodiment of an environmental pollutant detection device of the present invention;

[0049] Figure 5 It is a schematic structural diagram of the fourth cover plate of the present invention.

[0050] In the accompanying drawings: 100, glass substrate; 110, titanium coating; 120, first aluminum coating; 130, anodized aluminum layer; 131, array pattern anodized aluminum layer; 140, second aluminum coating; 141, array pattern aluminum coating; 150, gold coating; 200, first inlet unit; 210, first inlet; 220, second inlet; 230, third inlet; 240, first cover plate; 300, first capillary array; 400, detection unit; 410, fourth cover plate; 411, microfluidic channel; 500, blocking unit; 510, first protrusion; 520, second protrusion; 600, second capillary array; 710, second inlet unit; 711, second cover plate; 720, outlet unit; 721, third cover plate. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with specific implementation methods. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams, not actual drawings, and cannot be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0052] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0053] Embodiment 1

[0054] like Figure 1 to Figure 2 The present invention shows an embodiment of a method for preparing an environmental pollutant detection device, comprising the following steps:

[0055] S1. Select a glass substrate 100, and sequentially locate the first inlet unit 200, the first capillary array 300, the detection unit 400, the blocking unit 500, and the outflow unit on the glass substrate 100; in this embodiment, the size of the glass substrate 100 can be selected as 25 mm*75 mm, and the glass substrate 100 is an ITO glass substrate;

[0056] S2. Printing a nanopore thin film sensor array on the glass substrate 100 at a position corresponding to the detection unit 400 by anodized aluminum oxide (AAO) photolithography process;

[0057] S3. Printing the first inlet unit 200 and the first capillary array 300 at positions corresponding to the first inlet unit 200 and the first capillary array 300 by SU-8 photolithography; wherein the setting direction from the first inlet unit 200 to the detection unit 400 is parallel to the capillary force direction of the first capillary array 300;

[0058] S4. Using SU-8 photolithography process to print the blocking unit 500 and the outflow unit at the positions corresponding to the blocking unit 500 and the outflow unit; wherein the outflow unit includes a second capillary array 600, a second inlet unit 710, and an outlet unit 720, and the second inlet unit 710 and the outlet unit 720 are respectively located at two ends of the second capillary array 600 along the capillary force direction; wherein there is no order between steps S3 and S4;

[0059] S5. Functionalize the nanopore film sensor array to obtain the detection unit 400.

[0060] like Figure 2 As shown, step S2 in this embodiment includes the following steps:

[0061] S21. The glass substrate 100 is cleaned with deionized water, acetone, and isopropanol for 15 minutes; then, a titanium coating layer 110 is prepared on the surface of the cleaned glass substrate 100 using an electron beam evaporation coating machine; wherein the thickness of the titanium coating layer 110 is 5 to 10 nm, and preferably, the thickness of the titanium coating layer 110 is 10 nm;

[0062] S22. A first aluminum coating layer 120 (99.999%) is prepared on the surface of the titanium coating layer 110 using an electron beam evaporation coating machine; wherein the thickness of the first aluminum coating layer 120 is 2 to 15 μm; preferably, the thickness of the first aluminum coating layer 120 is 2 μm;

[0063] S23. A DC voltage of 25 to 35 V is applied, and the glass substrate 100 after step S22 is placed in an acidic solution at 3 to 8° C. to anodize the first aluminum-plated layer 120 to generate an anodized aluminum layer 130; preferably, a DC voltage of 30 V is set, and the glass substrate 100 after step S22 is placed in 0.3 M oxalic acid at 5.8° C. to anodize the first aluminum-plated layer 120 to obtain an anodized aluminum layer 130;

[0064] S24. Preparing a second aluminum coating layer 140 on the surface of the anodized aluminum layer 130 using an electron beam evaporation coating machine; wherein the thickness of the second aluminum coating layer 140 is 100 to 200 nm; preferably, the thickness of the second aluminum coating layer 140 is 150 nm;

[0065] S25. The glass substrate 100 after step S24 is photoetched, and then the second aluminum-plated layer 140 is etched by an etching solution, so that the pattern of the nanopore thin film sensor array is revealed in the second aluminum-plated layer 140 and an array pattern aluminum-plated layer 141 is obtained; wherein the etching solution is a (H3PO4:CH3COOH:HNO3:H2O) solution; at this time, the surface of the array pattern aluminum-plated layer 141 also has a photoresist as a protective layer;

[0066] S26. The glass substrate 100 after step S25 is immersed in a corrosion solution to make the pattern of the array pattern aluminum plating layer 141 appear on the anodized aluminum layer 130 and obtain the array pattern anodized aluminum layer 131; wherein the corrosion solution is a mixed solution comprising 0.4M phosphoric acid and 0.2M chromic acid;

[0067] S27. Etch away the array pattern aluminum-plated layer 141 and the photoresist on its surface, and then use a magnetron sputtering coating machine to prepare a gold-plated layer 150 on the surface of the array pattern anodized aluminum layer 131 to form a nanopore thin film sensor array; wherein the thickness of the gold-plated layer 150 is 5 to 15 nm; preferably, the thickness of the gold-plated layer 150 is 10 nm.

[0068] In order to facilitate the functionalization of the nanopore film sensor array, the first inlet unit 200 includes a first inlet 210, a second inlet 220, and a third inlet 230 which are all connected to the first capillary array 300, and the surfaces of the first inlet 210, the second inlet 220, and the third inlet 230 are covered with a first cover plate 240 having a microchannel, and the microchannel is adapted to the first inlet 210, the second inlet 220, and the third inlet 230 and respectively constitutes a first microchannel, a second microchannel, and a third microchannel, as shown in FIG. Figure 4 shown.

[0069] Furthermore, the second inlet unit 710 includes a fourth inlet and a second cover plate 711 having a microchannel disposed on the surface of the fourth inlet, and the fourth inlet and the second cover plate 711 form a fourth microchannel. The outlet unit 720 includes an outlet and a third cover plate 721 having a microchannel disposed on the surface of the outlet, and the outlet and the third cover plate 721 form a fifth microchannel. Figure 4 In addition, a fourth cover plate 410 having a microfluidic channel 411 is provided on the surface of the nanopore film sensor array, as shown in FIG. Figure 4 and Figure 5 In this embodiment, the first cover plate 240, the second cover plate 711, the third cover plate 721, and the fourth cover plate 410 are all PDMS plates.

[0070] Step S5 includes the following steps:

[0071] S51. In order to enable the aptamer to attach to the nanopore film sensor array, 0.1 mM HSC was added to the first microchannel at a low temperature of 1 to 5°C. 10 COOH and 0.9 mM HSC8OH solution, the solution passes through the first capillary array 300 and enters the nanopore film sensor array and reacts for 8 to 12 hours, and then is washed with 99.99% ethanol solution; then, a cleaning step is performed;

[0072] S52. At room temperature, an activator is added dropwise to the first microchannel, and the activator enters the nanopore film sensor array after passing through the first capillary array 300 and reacts for 1 to 2 hours; then, a washing step is performed;

[0073] Among them, the activators include NHS and EDC;

[0074] S53. In a low temperature environment of 1 to 5° C., an aptamer corresponding to the sample to be detected is added dropwise to the microfluidic channel 411 , and the aptamer reacts with the nanopore film sensor array for 8 to 12 hours; then, a washing step is performed;

[0075] S54. At room temperature, ethanolamine is added dropwise to the third microchannel. After passing through the first capillary array 300, ethanolamine enters the nanopore film sensor array and reacts for 1 to 2 hours, which can be used to block the non-occupied sites activated by the activator in the nanopore film sensor array. Then, a cleaning step is performed.

[0076] It should be noted that the arrangement of dripping different liquids through the first microchannel, the second microchannel and the third microchannel in the above steps can prevent the liquids from reacting before entering the nanopore film sensor array.

[0077] Specifically, in steps S51 to S54, the cleaning step includes: adding PBS buffer to the first microchannel, the second microchannel, and the third microchannel, specifically, adding 150 μl of PBS buffer; after the PBS buffer reaches the blocking unit 500, adding PBS buffer to the fourth microchannel, so that the PBS buffer is discharged from the fifth microchannel, and repeating three times to complete the cleaning.

[0078] The detection unit 400, as a nanopore film sensor array functionalized according to the heavy metal ions in the corresponding environmental pollutants to be detected, has good specificity and good reusability; the setting of the first capillary array 300 and the second capillary array 600 can guide the rapid flow of liquid, and the amount of liquid lost is extremely small, which can significantly reduce the amount of detection reagent sample and cost; the setting of printing each unit on the glass substrate 100 makes the detection device prepared by the preparation method portable, can realize rapid detection in outdoor environments, and has a wide range of application scenarios; in the method of using the detection device, it is possible to determine whether the sample contains target heavy metal ions based on the change in the effective refractive index of the nanopore film and the offset result of the optical signal, thereby realizing rapid detection of heavy metal ions.

[0079] Embodiment 2

[0080] This embodiment is an embodiment of a method for using an environmental pollutant detection device. This embodiment is applied to the environmental pollutant detection device prepared by the preparation method described in Example 1. The method for using the environmental pollutant detection device includes the following steps:

[0081] I. The sample to be detected is dripped into the first inlet unit 200 and flows to the first capillary array 300. The sample to be detected spontaneously flows to the detection unit 400 due to the capillary force at the first capillary array 300 and reacts with the aptamer therein. At this time, the blocking unit 500 can block the sample to be detected at the detection unit 400 for sufficient reaction; specifically, the sample to be detected is dripped into the first microchannel, the second microchannel, and the third microchannel;

[0082] II. Using a broadband light source to illuminate the surface of the detection unit 400, the effective refractive index of the nanoporous film will change, and the reflected light signal will shift. According to the shift result of the light signal, it can be determined whether the sample contains target heavy metal ions; in this embodiment, the broadband light source can be set to a laser with a wavelength of 350nm to 1050nm;

[0083] Specifically, when the aptamer binds to the target heavy metal ions, such as silver ions and mercury ions, the effective refractive index of the nanoporous film will change. Therefore, when the broadband light source is irradiated to the surface of the detection unit 400, the light signal (interference fringes) reflected by the sensor will be displaced, thereby serving as a detection signal (RIFS); based on the light signal displacement result, it can be determined whether the sample contains heavy metal ions;

[0084] III. After the detection is completed, PBS buffer is continuously added to the second inlet unit 710, and the PBS buffer flows to the second capillary array 600; when the pressures on both sides of the blocking unit 500 are equal, the blocked sample will flow through the blocking unit 500 to the second capillary array 600 and be discharged through the outlet unit 720; it should be noted that both sides of the blocking unit 500 refer to the sides where the detection unit 400 and the second capillary array 600 are located.

[0085] Embodiment 3

[0086] like Figures 3 to 5 The embodiment of an environmental pollutant detection device of the present invention is shown, comprising a glass substrate 100, on which a first inlet unit 200, a first capillary array 300, a detection unit 400, a blocking unit 500, and a second capillary array 600 are sequentially connected; the detection unit 400 comprises a functionalized nanopore film sensor array; the capillary force direction of the first capillary array 300 is arranged along the direction from the first inlet unit 200 to the detection unit 400; a second inlet unit 710 and an outlet unit 720 are respectively arranged at both ends of the second capillary array 600 along the capillary force direction; the capillary force direction of the second capillary array 600 is not parallel to the capillary force direction of the first capillary array 300. The environmental pollutant detection device of the present invention can detect silver ions and mercury ions as low as 0.1 μM.

[0087] like Figure 3 As shown, the nanopore film sensor array can be arranged as 4*5 detection modules, and each detection module can be set to a size of 2mm*2mm.

[0088] like Figure 3 and Figure 4 As shown, the blocking unit 500 includes a plurality of blocking structures arranged in an array, and the blocking structures include a first protrusion 510 and a second protrusion 520. A concave portion is provided on the side of the first protrusion 510 close to the second capillary array 600, and the second protrusion 520 is provided at the concave portion. Specifically, the cross-sectional shape of the concave portion can be set to an isosceles trapezoid, and the cross-sectional shape of the first protrusion 510 can be set to a square shape after removing the isosceles trapezoidal concave portion; the cross-sectional shape of the second protrusion 520 can be set to a rectangular shape. In this embodiment, six arranged blocking structures can be provided.

[0089] like Figure 3 and Figure 4 As shown, the capillary force direction of the second capillary array 600 is perpendicular to the capillary force direction of the first capillary array 300; the first capillary array 300 is a micro-rectangular array, in which the micro-rectangular arrays are staggered between columns; the length of the micro-rectangular array is 600-800μm, and the width is 300-500μm. Preferably, the size of the micro-rectangular array is 800μm*500μm.

[0090] like Figure 4 As shown, the first inlet unit 200 includes a first inlet 210, a second inlet 220, and a third inlet 230, and the surfaces of the first inlet 210, the second inlet 220, and the third inlet 230 are covered with a first cover plate 240 having microchannels, and the microchannels are adapted to the first inlet 210, the second inlet 220, and the third inlet 230 and respectively constitute the first microfluidic channel, the second microfluidic channel, and the third microfluidic channel, which are all connected to the first capillary array 300. In this embodiment, the width of each inlet can be set to 6.8 mm.

[0091] like Figure 4 As shown, the second inlet unit 710 includes a fourth inlet and a second cover plate 711 with a microchannel disposed on the surface of the fourth inlet, the fourth inlet and the second cover plate 711 constitute a fourth microchannel, and the fourth microchannel is connected to the second capillary array 600. The outlet unit 720 includes an outlet and a third cover plate 721 with a microchannel disposed on the surface of the outlet, the outlet and the third cover plate 721 constitute a fifth microchannel, and the fifth microchannel is connected to the second capillary array 600. In addition, a fourth cover plate 410 with a microfluidic channel 411 is disposed on the surface of the detection unit 400, the microfluidic channel 411 is connected to the detection unit 400, and the fourth cover plate 410 is detachably disposed, as shown in FIG. Figure 4 and Figure 5 In this embodiment, the first cover plate 240, the second cover plate 711, the third cover plate 721, and the fourth cover plate 410 are all PDMS plates.

[0092] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing an environmental pollutant detection device, characterized in that: The steps include: S1. Selecting a glass substrate (100); S2. Printing a nanopore thin film sensor array on the glass substrate (100) using a photolithography process; S3. Printing a first inlet unit (200) and a first capillary array (300) on one side of the nanopore film sensor array using a photolithography process; wherein the first inlet unit (200) and the nanopore film sensor array are respectively located at the first end and the second end of the first capillary array (300), and the capillary force direction of the first capillary array (300) is parallel to the extension direction of the first capillary array (300) from the first end to the second end; S4. Printing a blocking unit (500) and an outflow unit on the other side of the nanopore film sensor array by using a photolithography process; wherein the blocking unit (500) is located between the nanopore film sensor array and the outflow unit, and the outflow unit comprises a second capillary array (600), a second inlet unit (710), and an outlet unit (720), wherein the second inlet unit (710) and the outlet unit (720) are respectively located at the first end and the second end of the second capillary array (600), and the capillary force direction of the second capillary array (600) is parallel to the extension direction of the second capillary array (600) from the first end to the second end; wherein there is no order of precedence between steps S3 and S4; S5. Functionalize the nanopore film sensor array to obtain a detection unit (400).

2. The method for preparing the environmental pollutant detection device according to claim 1, characterized in that: Step S2 includes the following steps: S21. Electroplating titanium on the cleaned glass substrate (100) to obtain a titanium coating layer (110); S22. Electroplating aluminum on the titanium coating layer (110) to obtain a first aluminum coating layer (120); S23. Anodizing the first aluminum-plated layer (120) to obtain an anodized aluminum layer (130); S24. Electroplating aluminum on the anodized aluminum layer (130) to obtain a second aluminum-plated layer (140); S25. Photolithography is performed on the glass substrate (100) after completing step S24, and then the second aluminum coating layer (140) is etched by an etching solution to make the pattern of the nanopore film sensor array appear on the second aluminum coating layer (140) and obtain an array pattern aluminum coating layer (141); S26. Immersing the glass substrate (100) after completing step S25 into a corrosion solution, so that the pattern of the array pattern aluminum plating layer (141) appears on the anodized aluminum layer (130) and an array pattern anodized aluminum layer (131) is obtained; S27. Etch away the array pattern aluminum plating layer (141), and then plate gold on the array pattern anodized aluminum layer (131) to obtain a gold plating layer (150), thereby forming the nanopore thin film sensor array.

3. The method for preparing the environmental pollutant detection device according to claim 2, characterized in that: In step S21, an electron beam evaporation coating machine is used to prepare the titanium coating layer (110), wherein the thickness of the titanium coating layer (110) is 5 to 10 nm; In step S22, the first aluminum coating layer (120) is prepared using an electron beam evaporation coating machine, wherein the thickness of the first aluminum coating layer (120) is 2 to 15 μm; In step S23, a direct current voltage of 25 to 35 V is applied and the glass substrate (100) after step S22 is placed in an acid solution at 3 to 8° C. for anodization to generate the anodized aluminum layer (130); In step S24, the second aluminum coating layer (140) is prepared by using an electron beam evaporation coating machine, and the thickness of the second aluminum coating layer (140) is 100-200 nm; In step S25, the etching solution is a (H3PO4:CH3COOH:HNO3:H2O) solution; In step S26, the etching solution is a mixed solution containing 0.4M phosphoric acid and 0.2M chromic acid; In step S27, a magnetron sputtering coating machine is used to prepare the gold-plated layer (150), and the thickness of the gold-plated layer (150) is 5 to 15 nm.

4. The method for preparing the environmental pollutant detection device according to any one of claims 1 to 3, characterized in that: Step S5 includes the following steps: S51. Add 0.1 mM HSC to the nanopore film sensor array under low temperature. 10 COOH and 0.9 mM HSC8OH solution and react, then wash with ethanol solution; S52. Adding an activator to the nanopore film sensor array; S53. Under low temperature conditions, adding an aptamer corresponding to the sample to be detected to the nanopore film sensor array for reaction; S54. adding ethanolamine to the nanopore film sensor array to block the non-occupied sites activated by the activator; After each of the above steps is completed, a cleaning step is performed before proceeding to the next step.

5. The method for preparing the environmental pollutant detection device according to claim 4, characterized in that: In step S51, a solution is added at 1 to 5°C and reacted for 8 to 12 hours, and then washed with an ethanol solution; in step S52, the activator is added at room temperature and reacted for 1 to 2 hours, and the activator includes NHS and EDC; in step S53, the aptamer is added at 1 to 5°C and reacted for 8 to 12 hours; in step S54, ethanolamine is added at room temperature and reacted for 1 to 2 hours.

6. The method for preparing the environmental pollutant detection device according to claim 4, characterized in that: The cleaning step includes: dripping PBS buffer from the first inlet unit (200), and after the PBS buffer reaches the blocking unit (500), dripping PBS buffer from the second inlet unit (710), so that the PBS buffer is discharged from the outlet unit (720), and repeating multiple times to complete the cleaning.

7. A method for using the environmental pollutant detection device prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The steps include: I. dripping the sample to be detected from the first inlet unit (200) and flowing to the first capillary array (300), the sample to be detected spontaneously flows to the detection unit (400) due to the action of capillary force at the first capillary array (300) and reacts with the aptamer therein, and at this time, the blocking unit (500) can block the sample to be detected at the detection unit (400) for sufficient reaction; II. Using a broadband light source to illuminate the surface of the detection unit (400), the effective refractive index of the nanoporous film will change, and the reflected light signal will shift. According to the shift result of the light signal, it can be determined whether the sample contains target heavy metal ions; III. After the detection is completed, buffer solution is continuously added to the second inlet unit (710), and the buffer solution flows to the second capillary array (600); when the pressures on both sides of the blocking unit (500) are equal, the blocked sample will flow through the blocking unit (500) to the second capillary array (600) and be discharged through the outlet unit (720).

8. An environmental pollutant detection device, characterized in that: The invention comprises a glass substrate (100), on which a first inlet unit (200), a first capillary array (300), a detection unit (400), a blocking unit (500), and a second capillary array (600) are sequentially connected and arranged; the detection unit (400) comprises a functionalized nanopore film sensor array; the capillary force direction of the first capillary array (300) is arranged along the direction from the first inlet unit (200) to the detection unit (400); a second inlet unit (710) and an outlet unit (720) are respectively arranged at both ends of the second capillary array (600) along the capillary force direction; the capillary force direction of the second capillary array (600) is not parallel to the capillary force direction of the first capillary array (300).

9. The environmental pollutant detection device according to claim 8, characterized in that: The blocking unit (500) comprises a plurality of blocking structures arranged in an array, wherein the blocking structures comprise a first protrusion (510) and a second protrusion (520), wherein a concave position is provided on one side of the first protrusion (510) close to the second capillary array (600), and the second protrusion (520) is provided at the concave position.

10. The environmental pollutant detection device according to claim 8, characterized in that: The capillary force direction of the second capillary array (600) is perpendicular to the capillary force direction of the first capillary array (300); the first capillary array (300) is a micro-rectangular array, in which micro-rectangular arrays are arranged alternately between rows; the length of the micro-rectangular array is 600-800 μm, and the width is 300-500 μm.

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