Trace sulfamethoxazole detection device based on flowing potential and use method thereof

Abstract

The invention relates to the technical field of environment monitoring, in particular to a trace sulfamethoxazole detection device based on flow potential and a use method of the trace sulfamethoxazole detection device. The device comprises an air pump, a sample introduction pool, a micro-channel clamping unit, a waste liquid pool, a voltage detection unit, a central control unit and a display. A molecularly imprinted polymer micro-channel array is arranged in the micro-channel clamping unit, a first electrode and a second electrode are arranged at the two ends of the micro-channel clamping unit respectively, and the flowing potential is measured through the voltage detection unit. The central control unit controls the on-off of the air pump and the voltage detection unit, the working solution is controlled to flow through the micro-channel array to generate flowing potential at the two ends of the channel, the SMX concentration in the sample to be detected is analyzed according to the measured voltage, and the result is displayed on the display. The method realizes high-sensitivity detection of SMX through a flowing potential principle, has the advantages of simplicity in operation, rapidness in detection and high sensitivity, and is suitable for rapid detection of trace SMX in an environmental water sample.

Description

Technical Field

[0001] This invention patent relates to the technical field of antibiotic detection, and specifically relates to a detection device for trace sulfamethoxazole based on streaming potential and its usage method. Background Art

[0002] Sulfamethoxazole (SMX) is a widely used antibiotic, commonly used in human medicine and animal husbandry. However, the problem of SMX residues in the environment is becoming increasingly serious. It enters environmental media such as water bodies and soils through wastewater discharge, agricultural runoff, etc., which may cause microbial drug resistance, disrupt the ecological balance, and even threaten human health through food chain enrichment. Therefore, rapid and accurate detection of SMX concentration in the environment is of great significance for environmental pollution prevention and control and ecological security.

[0003] Currently, the detection methods for SMX mainly include high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), enzyme-linked immunosorbent assay (ELISA), etc. Although these methods have high sensitivity and accuracy, they also have obvious deficiencies, such as long detection cycles, limited sensitivity, large equipment volume, high cost, and complex operations. These problems make the existing methods unable to meet the actual requirements of rapid, portable, and real-time monitoring of SMX in environmental detection.

[0004] In recent years, detection methods based on electrochemical sensing technology have received extensive attention due to their high sensitivity, fast response speed, and simple operation. Streaming Potential is a technology based on electrokinetic phenomena. Its principle is that when an electrolyte solution flows in a microchannel, due to the existence of the double electric layer at the solid-liquid interface, a potential difference will be generated at both ends of the channel, namely the streaming potential. This technology has been widely used in fields such as surface charge characterization and microfluidic chip design. However, the existing streaming potential technology is mainly used for basic research and has not been used for the detection of SMX. This is mainly due to the following limitations: the lack of specific SMX capture probes, the inability to selectively adsorb SMX to the channel surface, etc. These limitations make the existing streaming potential technology unable to meet the requirements of rapid SMX detection. To address the above problems, the present invention proposes a rapid SMX detection device based on streaming potential. This device uses a molecularly imprinted polymer (MIP) with good stability and high specificity as the microchannel material, which can selectively recognize and adsorb SMX molecules. By measuring the change in streaming potential at both ends of the microchannel, high-precision and rapid determination of SMX concentration in the sample can be achieved. Summary of the Invention

[0005] In view of the technical problems mentioned in the above background art, a detection device for trace sulfamethoxazole based on streaming potential and its usage method are provided.

[0006] The technical means adopted by the present invention are as follows:

[0007] A detection device for trace sulfamethoxazole based on streaming potential, comprising: an air pump, a sampling pool, a microchannel clamping unit, a voltage detection unit, a waste liquid pool, a central control unit and a display;

[0008] Connect the air pump to the sampling pool through an air pipe, connect the sampling pool, the microchannel clamping unit and the waste liquid pool through liquid pipelines to establish a liquid path; connect the voltage detection unit to the left pressure measuring electrode and the right pressure measuring electrode in the microchannel clamping unit, and connect the voltage detection unit, the air pump and the display to the central control unit; collect the sample to be measured, load the sample to be measured into the sampling pool, the central control unit controls the air pump, and add the sample to be measured into the chamber of the microchannel clamping unit at a constant pressure. After the sample to be measured contacts the MIP microchannel array for 10 min to 30 min, then pump the sample to be measured into the reaction chamber, detect it through the voltage detection unit, and the control unit analyzes the concentration in the sample to be measured according to the measured voltage and displays the result on the display.

[0009] Further, the air pump is connected to the sampling pool through an air pipe, and the air pump is used to pump compressed air into the sampling pool; the sampling pool is used to store the working solution; two through holes are provided on the upper cover of the sampling pool for setting the air pipe and the liquid pipe; the air pipe is arranged above the liquid level of the solution, and the liquid pipe is arranged at the bottom of the pipe; the other end of the liquid pipe is connected to the microchannel clamping unit, and the air pump pumps gas into the sampling pool to generate a positive pressure above the liquid level, controlling the working solution to flow into the microchannel clamping unit.

[0010] Further, the microchannel clamping unit includes: a sampling port, a front cover, a left pressure measuring joint, a right pressure measuring joint, a rear cover, a sample outlet, a cylinder wall and a molecularly imprinted polymer microchannel array;

[0011] The cylinder wall is a hollow cylinder with uniform thickness; through holes for the wires to pass through are provided on the left and right sides of the cylinder wall, and the aperture of the wire holes is slightly smaller than the wire to form an interference fit to ensure the sealing of the liquid; the front cover and the rear cover are respectively provided with a liquid inlet and a liquid outlet; the joint of the liquid inlet is connected to the outlet of the sampling pool, and the inlet of the waste liquid pool is connected to the joint of the liquid outlet. During normal operation, the solution flows from the sampling pool through the liquid inlet joint into the microchannel clamping unit and then flows out to the waste liquid pool through the liquid outlet.

[0012] The molecularly imprinted polymer microchannel array is prepared by thermal polymerization; the outer diameter of the molecularly imprinted polymer microchannel array is slightly larger than the inner diameter of the cylinder wall, and the molecularly imprinted polymer microchannel is arranged at the central position of the cylinder wall.

[0013] Further, the working solution is a potassium chloride or sodium chloride solution with a concentration of 0.1 nmol / L - 10 mmol / L.

[0014] Further, the diameters of the front cover and the rear cover are both the same as the diameter of the cylinder wall; the front cover and the rear cover are respectively arranged at both ends of the cylinder wall to form a sealed chamber.

[0015] Further, a first electrode and a second electrode are arranged on the left and right sides of the molecularly imprinted polymer microchannel array; the first electrode and the second electrode are connected to the positive and negative electrodes of the voltage detection unit through wires passing through the wire holes to measure the streaming potential on both sides of the microchannel array.

[0016] Further, the voltage detection unit includes: a voltage sensor and a digital-to-analog conversion module; the voltage detection unit is used to measure the streaming potential generated at both ends of the microchannel array when the liquid flows through, and convert the analog signal output by the high-precision voltage sensor into a digital signal.

[0017] Further, the central control unit is connected to the air pump, the voltage detection unit, and the display, and is used to output control signals to the air pump and the voltage detection unit, control the opening and closing of the air pump and the measurement unit, realize the pumping of the liquid, and receive and save the measurement signals output by the voltage detection unit, and analyze the concentration in the sample to be measured according to the measured voltage.

[0018] The present invention also includes a method for using a detection device for trace sulfamethoxazole based on streaming potential, including the following steps:

[0019] S1. Connect the air pump to the sample injection pool through an air pipe, and connect the sample injection pool, the microchannel clamping unit, and the waste liquid pool through a liquid pipeline to establish a liquid path;

[0020] S2. Connect the voltage detection unit to the left and right pressure electrodes in the microchannel clamping unit, and connect the voltage detection unit, the air pump, and the display to the central control unit;

[0021] S3. Collect the sample to be measured, load the sample to be measured into the sample injection pool, the central control unit controls the air pump, adds the sample to be measured into the chamber of the microchannel clamping unit at a constant pressure, after the sample to be measured contacts the MIP microchannel array for 10 min - 30 min, then pump the sample to be measured into the reaction chamber, detect through the voltage detection unit, and the control unit analyzes the concentration in the sample to be measured according to the measured voltage and displays the result on the display.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention uses a molecularly imprinted polymer (MIP) microchannel array as the core detection material, which can specifically recognize and adsorb sulfamethoxazole (SMX) molecules, significantly improving the selectivity and sensitivity of detection. Through the principle of streaming potential, high-precision detection of trace SMX can be achieved, meeting the detection requirements for trace SMX in environmental water samples.

[0024] The device of the present invention has a simple structure and a convenient operation process, without the need for complex sample pretreatment steps. Through the central control unit, automatic control is realized, and the detection process is fast and efficient. The single detection time only takes 10 - 30 minutes, significantly shortening the detection cycle, and is suitable for on-site rapid detection and real-time monitoring.

[0025] Compared with traditional detection methods such as HPLC and GC-MS, the device of the present invention does not require expensive large-scale instrument equipment, and has low consumable costs and is easy to maintain. The device is small and portable, suitable for use in the field or outdoor environment, meeting the requirements for portable detection equipment in environmental monitoring.

[0026] The MIP material used in the present invention has good stability, reducing the generation of waste during the detection process, which conforms to the concept of green environmental protection. At the same time, the reagents used in the device are common electrolyte solutions (such as KCl or NaCl), which are non-polluting to the environment.

[0027] The present invention is not only applicable to the detection of SMX in environmental water samples, but also can be extended to the detection of other antibiotics or organic pollutants by replacing the template molecule in the MIP material, having a wide range of application prospects. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of the device of the present invention.

[0030] Figure 2 It is a schematic structural diagram of the microchannel clamping unit of the present invention.

[0031] Figure 3 It is a detailed view of the MIP microchannel array of the present invention.

[0032] Figure 4 It is a detection signal diagram of the present invention.

[0033] In the figure: 1 is an air pump; 2 is a sampling cell; 3 is a microchannel clamping unit; 4 is a waste liquid pool; 5 is a display; 6 is a central control system; 7 is a voltage detection unit; 3-1 is a sampling port; 3-2 is a front cover; 3-3 is a left pressure measuring joint; 3-4 is a right pressure measuring joint; 3-5 is a rear cover; 3-6 is a sample outlet; 3-7 is a molecularly imprinted polymer microchannel array. Specific embodiments

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] At the solid-liquid interface, the solid surface usually carries a certain charge (for example, due to the ionization of surface groups or ion adsorption), and the counterions in the liquid will aggregate near the solid surface under the action of electrostatic force to form an electric double layer. The electric double layer consists of a compact layer (Stern layer) and a diffuse layer. When a fluid (such as water or an electrolyte solution) passes through a porous medium or a capillary under the action of an external force (such as a pressure difference), the ions in the diffuse layer of the fluid will be affected by the shear force and move. Since the ions in the compact layer are strongly bound to the solid surface and usually remain stationary, while the counterions in the diffuse layer flow with the fluid. The fluid flow causes the separation of the counterions in the diffuse layer from the charges in the compact layer, resulting in an imbalance in the charge distribution in the flow direction and generating a potential difference, that is, the streaming potential. The magnitude of the streaming potential is closely related to factors such as the flow rate of the fluid, the charge density at the solid-liquid interface, the electrolyte concentration, and the geometric structure of the medium.

[0037] Therefore, as Figure 1As shown in the figure, the present invention provides a detection device for trace sulfamethoxazole based on streaming potential. The detection device for trace sulfamethoxazole includes an air pump, a sample injection cell, a microchannel clamping unit, a voltage detection unit, a waste liquid cell, a central control unit, and a display. The air pump is connected to the sample injection cell through an air pipe, and the sample injection cell, the microchannel clamping unit, and the waste liquid cell are connected through liquid pipelines to establish a liquid path. The voltage detection unit is connected to the left pressure measurement electrode and the right pressure measurement electrode in the microchannel clamping unit, and the voltage detection unit, the air pump, and the display are connected to the central control unit. The sample to be measured is collected and loaded into the sample injection cell. The central control unit controls the air pump to add the sample to be measured into the chamber of the microchannel clamping unit at a constant pressure. After the sample to be measured contacts the MIP microchannel array for 10 min to 30 min, the sample to be measured is then pumped into the reaction chamber and detected by the voltage detection unit. The control unit analyzes the concentration of the sample to be measured based on the measured voltage and displays the result on the display.

[0038] In this application, the air pump is connected to the sample injection cell through an air pipe and is used to pump compressed air into the sample injection cell. The sample injection cell is made of plastic and is used to store the working solution. The sample injection cell is a cylindrical barrel with a diameter of 3 - 5 cm and a height of 8 - 10 cm. There are two through holes on the upper cover for inserting the air pipe and the liquid pipe. The air pipe is inserted above the liquid level of the solution, and the liquid pipe is inserted at the bottom of the pipe. The other end of the liquid pipe is connected to the microchannel clamping unit. By pumping gas into the sample injection cell through the air pump, a positive pressure is generated above the liquid level to control the working solution to flow into the microchannel clamping unit. The working solution is a potassium chloride or sodium chloride solution with a concentration of 0.1 nmol / L - 10 mmol / L.

[0039] As a preferred embodiment, in this application, the microchannel clamping unit includes a sample inlet, a front cover, a left pressure measurement joint, a right pressure measurement joint, a rear cover, a sample outlet, a barrel wall, and a molecularly imprinted polymer microchannel array. The barrel wall, the front cover, and the rear cover are made of glass. The barrel wall is a hollow cylinder with uniform thickness, with a diameter of 8 - 10 cm and a length of 20 - 30 cm. There are wire passing holes on both the left and right sides of the barrel wall for the wires to pass through. The diameter of the wire holes is slightly smaller than the wires to form an interference fit to ensure the liquid seal. The front cover and the rear cover are circular, with the same diameter as the barrel wall, and are respectively placed at both ends of the barrel wall to form a sealed chamber. There are a liquid inlet and a liquid outlet on the front cover and the rear cover respectively. The liquid inlet joint is connected to the outlet of the sample injection cell, and the inlet of the waste liquid cell is connected to the liquid outlet joint. During normal operation, the solution flows from the sample injection cell through the liquid inlet joint into the microchannel clamping unit and then flows out to the waste liquid cell through the liquid outlet.

[0040] Preferably, the molecularly imprinted polymer microchannel array is prepared by thermal polymerization. Its characteristics are similar to those of honeycomb coal. The overall structure is a cylinder with a diameter of 8 - 10 cm and a length of 1 - 10 cm, and it contains 30 - 100 microchannels with a diameter of 100 - 500 μm and a length of 1 - 10 cm inside. The outer diameter of the molecularly imprinted polymer microchannel array is slightly larger than the inner diameter of the cylinder wall and is placed at the center position of the cylinder wall. The first electrode and the second electrode are made of platinum and are filaments with a diameter of 1 - 3 mm and a length of 0.5 - 2 cm. They are placed inside the cylinder wall, on the left and right sides of the molecularly imprinted polymer microchannel array respectively, and are connected to the positive and negative electrodes of the voltage detection unit through wires passing through the wire holes to measure the streaming potential on both sides of the microchannel array. The waste liquid pool is made of plastic and is connected to the sample outlet hole of the microchannel clamping unit through a liquid pipe to receive the working solution flowing out of the microchannel clamping unit. The waste liquid pool is a cylinder with a diameter of 3 - 5 cm and a height of 8 - 10 cm.

[0041] In this application, the voltage detection unit includes a high-precision voltage sensor and an analog-to-digital conversion module, which are used to measure the streaming potential generated at both ends of the microchannel array when the liquid flows through, and convert the analog signal output by the high-precision voltage sensor into a digital signal. The central control unit is connected to the air pump, the voltage detection unit, and the display, and is used to output control signals to the air pump and the voltage detection unit, control the opening and closing of the air pump and the measurement unit, realize the pumping of the liquid, and receive and save the measurement signals output by the voltage detection unit, and analyze the concentration in the sample to be measured according to the measured voltage.

[0042] Preferably, in this application, the display is a liquid crystal display screen, which is connected to the central control unit to display the concentration in the sample to be measured.

[0043] Preferably, the preparation method of the above-mentioned molecularly imprinted polymer microchannel array includes the following steps:

[0044] D1. Mold preparation: Select a flat plate-shaped substrate, and vertically arrange a number of parallel metal wires on the surface of the substrate to form a mold assembly with a predetermined channel structure;

[0045] D2. Mold assembly: Place the above-mentioned mold assembly inside a cylindrical container to ensure that there is an appropriate distance between the mold and the inner wall of the container;

[0046] D3. Preparation of the prepolymer solution: Dissolve the template molecule (SMX) in acetonitrile, add the functional monomer (MAA), the cross-linking agent (TRI), and the initiator (AIBN). Degas the solution in an ultrasonic bath for 5 minutes, then purge with nitrogen for 15 minutes and keep it under nitrogen. Carry out precipitation polymerization reaction at 65 °C for 24 hours. Centrifuge to separate the polymer, wash the polymer with methanol - acetic acid (9:1). Subsequently, wash the polymer with methanol until no template can be detected from the washing solvent by HPLC.

[0047] D4. Solution perfusion: Inject the prepolymer solution into a cylindrical container equipped with a mold so that the solution completely submerges the mold assembly;

[0048] D5. Curing treatment: Heat at 60 °C for 24 hours to form a solid polymer MIP;

[0049] D6. Demolding treatment: Take out the cured solid from the container and axially extract the metal wire to form a through-channel in the solid corresponding to the shape of the metal wire;

[0050] D7. Structure characterization: Finally, a porous structural material with regularly arranged channels is obtained, and the channel distribution characteristics are similar to those of a honeycomb coal structure.

[0051] In this application, the length of the MIP material is 1 - 10 cm, the left and right diameters are 8 - 10 cm. The channel diameter in the MIP material is 100 - 500 μm and the length is 1 - 10 cm.

[0052] Example 1:

[0053] As an embodiment of the present invention, this embodiment provides a detection device for trace sulfamethoxazole based on streaming potential, including: an air pump 1, a sampling pool 2, a microchannel clamping unit 3, a waste liquid pool 4, a display 5, a central control system 6, and a voltage detection unit 7.

[0054] Connect the air pump 1 to the sampling pool 2 through an air pipe, connect the sampling pool 2, the microchannel clamping unit 3, and the waste liquid pool 4 through a liquid pipeline to establish a liquid path; connect the voltage detection unit 7 to the left and right pressure measuring electrodes in the microchannel clamping unit 3, and connect the voltage detection unit 7, the air pump 1, and the display 5 to the central control unit 6; collect the sample to be tested, load the sample to be tested into the sampling pool 2, the central control unit 6 controls the air pump 1, and adds the sample to be tested into the chamber of the microchannel clamping unit 3 at a constant pressure. After the sample to be tested contacts the MIP microchannel array for 10 min - 30 min, then pump the sample to be tested into the reaction chamber, detect through the voltage detection unit, and the control unit analyzes the concentration in the sample to be tested according to the measured voltage and displays the result on the display.

[0055] The material of the sampling pool is plastic and is used to store the working solution; the sampling pool is a round barrel with a diameter of 4 cm and a height of 9, and the upper cover is provided with two through holes for inserting the air pipe and the liquid pipe. The air pipe is inserted above the liquid level of the solution, and the liquid pipe is inserted at the bottom of the pipe; the other end of the liquid pipe is connected to the microchannel clamping unit, and gas is pumped into the sampling pool through the air pump to generate a positive pressure above the liquid level to control the working solution to flow into the microchannel clamping unit; the working solution is a potassium chloride or sodium chloride solution with a concentration of 5 nmol / L.

[0056] As Figure 2, the microchannel clamping unit 3 includes a molecularly imprinted polymer microchannel array 3-7. The left end of the microchannel clamping unit 3 is provided with a sample inlet 3-1 and a left pressure measuring joint 3-3, and the right end of the microchannel clamping unit 3 is provided with a sample outlet 3-6 and a right pressure measuring joint 3-4. The left pressure measuring joint 3-3, the sample inlet 3-1, the right pressure measuring joint 3-4 and the sample outlet 3-6 are all communicated with the molecularly imprinted polymer microchannel array 3-7; the left pressure measuring joint 3-3 and the right pressure measuring joint 3-4 are respectively connected to the first electrode and the second electrode, and are respectively connected to the positive and negative electrodes of the voltage detection unit through wires; the sample inlet 3-1 is connected to the outlet of the sample injection pool 2, the inlet of the sample injection pool 2 is connected to the air pump 1, the inlet of the waste liquid pool 4 is connected to the sample outlet 6, and the working solution circulates between the sample injection pool 2, the waste liquid pool 4 and the microchannel clamping unit 3.

[0057] In a preferred embodiment of the present invention, the microchannel clamping unit includes a front cover, a rear cover, a barrel wall and a molecularly imprinted polymer microchannel array. The barrel wall, the front cover and the rear cover are made of glass. The barrel wall is a hollow cylinder with uniform thickness, with a diameter of 8 cm and a length of 20 cm. The front cover and the rear cover are circular, with a diameter consistent with that of the barrel wall, and are respectively placed at both ends of the barrel wall to form a sealed chamber. The front cover is provided with a sample inlet, and the rear cover is provided with a sample outlet. The sample inlet is connected to the outlet of the sample injection pool, and the sample outlet is connected to the inlet of the waste liquid pool, ensuring that the working solution flows from the sample injection pool through the sample inlet into the microchannel clamping unit and finally flows out through the sample outlet to the waste liquid pool.

[0058] Further, through holes for wires to pass through are provided on both the left and right sides of the barrel wall. The aperture of the wire holes is slightly smaller than the diameter of the wire to form an interference fit to ensure liquid tightness. A sealing device is filled between the wire and the through hole to further prevent liquid leakage.

[0059] Further, the molecularly imprinted polymer microchannel array is prepared by a thermal polymerization method. Its structure is similar to that of honeycomb coal. It is a cylindrical shape with a diameter of 8 cm and a length of 10 cm as a whole, and contains 30 microchannels with a diameter of 100 μm and a length of 10 cm inside. The outer diameter of the molecularly imprinted polymer microchannel array is slightly larger than the inner diameter of the barrel wall and is placed at the center of the barrel wall to ensure its close fit with the barrel wall.

[0060] Further, the first electrode and the second electrode are made of platinum and are thin wires with a diameter of 1 mm and a length of 1 cm. They are respectively placed inside the barrel wall on the left and right sides of the molecularly imprinted polymer microchannel array. The electrodes are connected to the positive and negative electrodes of the voltage detection unit through wires passing through the through holes, and are used to measure the streaming potential on both sides of the microchannel array.

[0061] The waste liquid pool is made of plastic and is connected to the sample outlet of the microchannel clamping unit through a liquid pipe, and is used to receive the working solution flowing out of the microchannel clamping unit. The waste liquid pool is a cylinder with a diameter of 3 cm and a height of 8 cm, which is convenient for observing the liquid level and waste liquid treatment.

[0062] In a preferred embodiment of the present invention, the microchannel clamping unit is a cylindrical glass container with a height of 20 cm and a bottom circle diameter of 8 cm. The molecularly imprinted polymer microchannel array is cylindrical with a diameter of 8 cm and a length of 10 cm, and contains 30 microchannels with a diameter of 100 μm and a length of 10 cm inside. The first electrode and the second electrode are platinum electrodes to ensure high-precision and stable measurement.

[0063] Example 2:

[0064] As an embodiment of the present invention, this embodiment provides a method for detecting trace SMX based on streaming potential, including the following steps:

[0065] S1. Connect the liquid pipeline;

[0066] Connect the air pump and the injection cell through an air pipe, and connect the injection cell, the microchannel clamping unit, and the waste liquid cell through a liquid pipeline to establish a liquid path.

[0067] S2. Connect the control circuit;

[0068] Connect the voltage detection unit to the left pressure measurement electrode and the right pressure measurement electrode in the microchannel clamping unit, and connect the voltage detection unit, the air pump, and the display to the central control system.

[0069] S3. Sample detection;

[0070] Collect the sample and load it into the injection cell. The central control unit controls the air pump to add 0.1 ml - 2 ml of the solution into the chamber of the microchannel clamping unit at a constant pressure. The sample to be measured contacts the MIP microchannel array. After 10 min - 30 min, pump another 0.1 ml - 2 ml of the solution into the reaction chamber, detect it through the voltage detection unit, and the control unit analyzes the concentration in the sample to be measured according to the measured voltage and displays the result on the display.

[0071] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0072] In the above embodiments of the present invention, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0073] In several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are merely illustrative. For example, the division of the units can be a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of units or modules can be in an electrical or other form.

[0074] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0075] In addition, in each embodiment of the present invention, the functional units can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0076] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention. The foregoing storage medium includes: various media such as USB flash drives, read-only memories (ROMs), random access memories (RAMs), mobile hard disks, magnetic disks, or optical discs that can store program codes.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of each embodiment of the present invention.

Claims

1. A detection device for trace sulfamethoxazole based on streaming potential, characterized in that, Including: An air pump, a sample injection cell, a microchannel clamping unit, a voltage detection unit, a waste liquid cell, a central control unit and a display; Connect the air pump to the sample injection cell through an air pipe, connect the sample injection cell, the microchannel clamping unit, and the waste liquid cell through a liquid pipeline to establish a liquid path; connect the voltage detection unit to the left pressure measurement electrode and the right pressure measurement electrode in the microchannel clamping unit, and connect the voltage detection unit, the air pump, and the display to the central control unit; collect the sample to be measured, load the sample to be measured into the sample injection cell, the central control unit controls the air pump, add the sample to be measured into the chamber of the microchannel clamping unit at a constant pressure, after the sample to be measured contacts the MIP microchannel array for 10 min to 30 min, then pump the sample to be measured into the reaction chamber, detect through the voltage detection unit, the control unit analyzes the concentration in the sample to be measured according to the measured voltage, and displays the result on the display.

2. The detection device for trace sulfamethoxazole based on streaming potential according to claim 1, characterized in that, The air pump is connected to the sample injection cell through an air pipe, and the air pump is used to pump compressed air into the sample injection cell; the sample injection cell is used to store the working solution; two through holes are provided on the upper cover of the sample injection cell for setting the air pipe and the liquid pipe; the air pipe is arranged above the liquid level of the solution, and the liquid pipe is arranged at the bottom of the pipe; the other end of the liquid pipe is connected to the microchannel clamping unit, and the air pump pumps gas into the sample injection cell to generate a positive pressure above the liquid level, controlling the working solution to flow into the microchannel clamping unit.

3. The detection device for trace sulfamethoxazole based on streaming potential according to claim 1, characterized in that, The microchannel clamping unit includes: a sample inlet, a front cover, a left pressure measurement joint, a right pressure measurement joint, a rear cover, a sample outlet, a cylinder wall, and a molecularly imprinted polymer microchannel array; The cylinder wall is a hollow cylinder with uniform thickness; through holes for the wires to pass through are provided on the left and right sides of the cylinder wall, and the diameter of the wire hole is slightly smaller than the wire to form an interference fit to ensure liquid sealing; an inlet and an outlet are respectively provided on the front cover and the rear cover; the joint of the inlet is connected to the outlet of the sample injection cell, and the inlet of the waste liquid cell is connected to the outlet joint. During normal operation, the solution flows from the sample injection cell through the inlet joint into the microchannel clamping unit, and then flows out through the outlet to the waste liquid cell; The molecularly imprinted polymer microchannel array is prepared by a thermal polymerization method; the outer diameter of the molecularly imprinted polymer microchannel array is slightly larger than the inner diameter of the cylinder wall, and the molecularly imprinted polymer microchannel is arranged at the center position of the cylinder wall.

4. The detection device for trace sulfamethoxazole based on streaming potential according to claim 2, characterized in that, The working solution is a potassium chloride or sodium chloride solution with a concentration of 0.1 nmol / L - 10 mmol / L.

5. The detection device for trace sulfamethoxazole based on streaming potential according to claim 1, wherein, The diameters of the front cover and the rear cover are both the same as the diameter of the cylinder wall; the front cover and the rear cover are respectively arranged at both ends of the cylinder wall to form a sealed chamber.

6. The detection device for trace sulfamethoxazole based on streaming potential according to claim 1, characterized in that, A first electrode and a second electrode are arranged on the left and right sides of the molecularly imprinted polymer microchannel array; the first electrode and the second electrode are connected to the positive and negative electrodes of the voltage detection unit through wires passing through the through holes to measure the streaming potential on both sides of the microchannel array.

7. The detection device for trace sulfamethoxazole based on streaming potential according to claim 1, wherein, The voltage detection unit includes: a voltage sensor and an analog-to-digital conversion module; the voltage detection unit is used to measure the streaming potential generated at both ends of the microchannel array when the liquid flows through, and convert the analog signal output by the high-precision voltage sensor into a digital signal.

8. The detection device for trace sulfamethoxazole based on streaming potential according to claim 1, wherein The central control unit is connected to the air pump, the voltage detection unit, and the display, and is used to output control signals to the air pump and the voltage detection unit, control the opening and closing of the air pump and the measurement unit, realize the pumping of the liquid, and receive and save the measurement signals output by the voltage detection unit, and analyze the concentration in the sample to be measured according to the measured voltage.

9. Method for using a detection device for trace sulfamethoxazole based on streaming potential, applying the device according to any one of claims 1-8, characterized in that, It includes the following steps: S1. Connect the air pump and the sample injection pool through an air pipe, and connect the sample injection pool, the microchannel clamping unit, and the waste liquid pool through a liquid pipeline to establish a liquid path. S2. Connect the voltage detection unit to the left pressure measurement electrode and the right pressure measurement electrode in the microchannel clamping unit, and connect the voltage detection unit, the air pump, and the display to the central control unit. S3. Collect the sample to be measured, load the sample to be measured into the sample injection pool, the central control unit controls the air pump, and add the sample to be measured into the chamber of the microchannel clamping unit at a constant pressure. After the sample to be measured contacts the MIP microchannel array for 10 min to 30 min, then pump the sample to be measured into the reaction chamber, detect it through the voltage detection unit, the control unit analyzes the concentration in the sample to be measured according to the measured voltage, and displays the result on the display.

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