Cu-EDTA (copper-ethylene diamine tetraacetic acid) detection device and method based on solid nanopore detection technology

Abstract

The invention discloses a Cu-EDTA (copper-ethylene diamine tetraacetic acid) detection device and method based on a solid nanopore detection technology. The method comprises the following steps: preparing an electrolyte solution; obtaining a to-be-detected object, and preparing standard Cu-EDTA solutions with different concentrations based on the to-be-detected object; the electrolyte solution and the standard Cu-EDTA solution are added to the two sides of the solid-state nanopore sensor in the fluid pool respectively; stable voltage is applied to the two sides of a nanopore of the solid nanopore sensor, a current signal is obtained through a signal acquisition system, and the concentration of Cu-EDTA is obtained based on analysis of the current signal. The detection method disclosed by the invention has the advantages of simplicity and convenience in operation, high sensitivity, high response speed and the like, can be widely applied to online monitoring and risk assessment of mining area water body pollutants, and provides scientific basis and technical support for mining area pollution abatement.

Description

Technical Field

[0001] The invention belongs to the technical field of rapid detection of environmental pollutants in mining areas, and in particular relates to a Cu-EDTA detection device and method based on solid-state nanopore detection technology. Background Art

[0002] As environmental pollution becomes increasingly serious, heavy metal pollution, especially the complex formed by copper (Cu) and the organic ligand EDTA (ethylenediaminetetraacetic acid), has become a focus of global attention. The Cu-EDTA complex has high stability and water solubility, and can exist in water for a long time, increasing the mobility and bioavailability of copper ions in the environment. This not only aggravates the degree of water pollution, but also increases its toxicity to aquatic organisms, thereby threatening ecological balance and human health.

[0003] Currently, the detection technology for heavy metal pollution faces many challenges. Although traditional analytical methods such as chemical analysis, spectroscopy and electrochemical sensors can detect the concentration of single metal ions, they often fail to provide sufficient sensitivity and real-time performance when dealing with complex metal-organic ligand complexes. In particular, the stability and low mobility of Cu-EDTA complexes make it difficult for traditional methods to perform rapid and accurate quantitative analysis. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a Cu-EDTA detection device and method based on solid-state nanopore detection technology to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides a Cu-EDTA detection device based on solid-state nanopore detection technology, comprising:

[0006] Fluid pool, solid-state nanopore sensor, voltage application device, signal acquisition system, data processing unit;

[0007] The solid-state nanopore sensor is installed in the middle of the fluid pool;

[0008] A voltage applying device, used to apply a stable voltage on both sides of the nanopore of the solid-state nanopore sensor to drive the Cu-EDTA molecules to pass through the nanopore;

[0009] A signal acquisition system, used to obtain current signals;

[0010] A data processing unit is used to obtain the concentration of Cu-EDTA according to the current signal.

[0011] Optionally, the diameter of the nanopore of the solid-state nanopore sensor is 1.5 nm.

[0012] Optionally, grooves are provided on both sides of the fluid pool, and guide holes are provided in the grooves, and the positive electrode and the negative electrode of the voltage applying device are respectively inserted into the guide holes on both sides of the fluid pool.

[0013] The present invention also provides a Cu-EDTA detection method based on solid-state nanopore detection technology, comprising:

[0014] Prepare electrolyte solution; obtain the object to be tested, and prepare standard Cu-EDTA solutions of different concentrations based on the object to be tested;

[0015] adding the electrolyte solution and the standard Cu-EDTA solution to both sides of the solid-state nanopore sensor in the fluid cell respectively;

[0016] A stable voltage is applied to both sides of the nanopore of the solid-state nanopore sensor, a current signal is acquired through a signal acquisition system, and the concentration of Cu-EDTA is obtained based on the current signal analysis.

[0017] Optionally, the electrolyte solution is a mixture of ammonia water and methanol, and the pH range of the electrolyte solution is 9.5-11.5.

[0018] Optionally, the process of obtaining the object to be tested includes:

[0019] After the tailings are collected, they are naturally air-dried and crushed, 0.01-0.02 g of the sample is weighed, and leached by vibration at a solid-liquid ratio of 10:1, and the leachate is used as the test object.

[0020] Optionally, the standard Cu-EDTA solution includes four concentrations: 0.6 mol / L, 0.8 mol / L, 1 mol / L and 1.2 mol / L.

[0021] Optionally, the stable voltage is 110mV.

[0022] Optionally, the process of obtaining the concentration of Cu-EDTA includes: analyzing the amplitude change and translocation time of the current signal, performing statistical analysis on the amplitude change and the translocation time, and obtaining the current characteristics and translocation signals of standard Cu-EDTA solutions of different concentrations; and obtaining the Cu-EDTA concentration of the Cu-EDTA complex solution to be detected based on the current characteristics and translocation signals of standard Cu-EDTA solutions of different concentrations.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The present invention proposes a Cu-EDTA composite pollutant detection method based on solid-state nanopore sensing technology, which achieves high-sensitivity, real-time monitoring of the Cu-EDTA complex by precisely controlling the pore size and surface characteristics of the nanopores and combining the principle of resistive pulse sensing. The detection method of the present invention has the advantages of simple operation, high sensitivity, fast response speed, etc., and can be widely used in online monitoring and risk assessment of water pollutants in mining areas, providing scientific basis and technical support for pollution control in mining areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 is a schematic diagram of a device according to an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the sample determination principle of an embodiment of the present invention, (a) is a schematic diagram of a nanopore detection device; (b) is a schematic diagram of a reference current; (c) and (d) are schematic diagrams of the blocking current generated by different sizes of analytes passing through the nanopore;

[0028] Figure 3 This is a current-time data diagram corresponding to different detection concentrations according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0031] Embodiment 1

[0032] like Figure 1-3 As shown, this embodiment provides a Cu-EDTA detection device based on solid-state nanopore detection technology, including:

[0033] Fluid pool, solid-state nanopore sensor, voltage application device, signal acquisition system, data processing unit;

[0034] The solid-state nanopore sensor is installed in the middle of the fluid pool;

[0035] A voltage applying device, used to apply a stable voltage on both sides of the nanopore of the solid-state nanopore sensor to drive the Cu-EDTA molecules to pass through the nanopore;

[0036] A signal acquisition system, used to obtain current signals;

[0037] A data processing unit is used to obtain the concentration of Cu-EDTA according to the current signal.

[0038] Furthermore, the diameter of the nanopore of the solid-state nanopore sensor is 1.5 nm.

[0039] Furthermore, grooves are provided on both sides of the fluid pool, and guide holes are provided in the grooves, and the positive electrode and the negative electrode of the voltage applying device are respectively inserted into the guide holes on both sides of the fluid pool.

[0040] Specifically, solid-state nanopore sensors with pore sizes ranging from 1.5 nm were used to detect the current blocking characteristics of Cu-EDTA complexes;

[0041] A voltage application device, used to apply a voltage of 110 mV on both sides of the nanopore to drive the Cu-EDTA molecules through the nanopore;

[0042] A signal acquisition system for real-time recording of current amplitude changes and translocation time when passing through the nanopore;

[0043] The data processing unit is used to count and analyze the detected current signal, generate a translocation time-amplitude scatter plot, a translocation time frequency distribution plot and a blocking amplitude frequency distribution plot, and extract the quantitative information of the Cu-EDTA concentration by a Gaussian fitting method.

[0044] The pore size of the solid-state nanopore is precisely controlled within the range of 1.5nm, which can achieve high-sensitivity detection of Cu-EDTA complexes. The voltage application device can form a stable electric field in the nanopore by applying a voltage of 110mV, ensuring that Cu-EDTA molecules pass through effectively and generate blocking current.

[0045] Figure 1 (d) is a Faraday shielding box, and the nanopore sensor is fixed on Figure 1 (e) is between the fluid pools shown in the figure, and the nanopore on the nanopore sensor becomes the only channel in the fluid pool, and the fluid pool is divided into two independent fluid pools by the nanopore sensor; Figure 1 (b) The power supply shown is used to apply electrical signals to both sides of the nanopore sensor;

[0046] Figure 1 (a) shows a data processing module for Figure 1Middle (c) The patch clamp amplifier (signal acquisition system) collects the electrical signal of the nanopore sensor and determines the baseline current and time current diagram.

[0047] In the design of solid-state nanopore sensor chips or test cells, a groove is opened at each end of the cell body for adding liquid, inserting electrodes, and ensuring that the solution can immerse the electrode surface. The groove usually forms a closed or semi-closed space with the sensor surface, where the liquid gathers and is connected to the other side through the nanopore in the center of the sensor. A guide hole is opened on the side wall or bottom of the groove to insert the electrode or wire from the outside into the solution so that the end of the electrode is immersed in the solution. The guide hole is used to fix the main working electrode or reference electrode, and there is also an auxiliary electrode in the groove. The working electrode is inserted near the nanopore to detect the signal; the counter electrode / auxiliary electrode is located in the groove on the other side to complete the circuit.

[0048] This embodiment also provides a Cu-EDTA detection method based on solid-state nanopore detection technology, including:

[0049] Prepare electrolyte solution; obtain the object to be tested, and prepare standard Cu-EDTA solutions of different concentrations based on the object to be tested;

[0050] adding the electrolyte solution and the standard Cu-EDTA solution to both sides of the solid-state nanopore sensor in the fluid cell respectively;

[0051] A stable voltage is applied to both sides of the nanopore of the solid-state nanopore sensor, a current signal is acquired through a signal acquisition system, and the concentration of Cu-EDTA is obtained based on the current signal analysis.

[0052] Furthermore, the electrolyte solution is a mixture of ammonia water and methanol, and the pH value of the electrolyte solution is in the range of 9.5-11.5.

[0053] Furthermore, the process of obtaining the object to be tested includes:

[0054] After the tailings are collected, they are naturally air-dried and crushed, 0.01-0.02 g of the sample is weighed, and leached by vibration at a solid-liquid ratio of 10:1, and the leachate is used as the test object.

[0055] Furthermore, the standard Cu-EDTA solution includes four concentrations: 0.6 mol / L, 0.8 mol / L, 1 mol / L and 1.2 mol / L.

[0056] Furthermore, the stable voltage is 110mV.

[0057] Furthermore, the process of obtaining the concentration of Cu-EDTA includes: analyzing the amplitude change and translocation time of the current signal, performing statistical analysis on the amplitude change and the translocation time, and obtaining the current characteristics and translocation signals of standard Cu-EDTA solutions of different concentrations; and obtaining the Cu-EDTA concentration of the Cu-EDTA complex solution to be detected based on the current characteristics and translocation signals of standard Cu-EDTA solutions of different concentrations.

[0058] Specifically, the Cu-EDTA sample solution to be tested is added into the fluid pool of the device; wherein the concentration of the Cu-EDTA sample solution is 0.6 mol / L, 0.8 mol / L, 1 mol / L, 1.2 mol / L. The specific solution is configured through the experimental steps, and it is ensured that the Cu-EDTA solution is in full contact with the electrodes on both sides of the fluid pool.

[0059] The fluid pool is a cavity divided into two parts by a solid-state nanopore sensor. One side is used as the "reference or electrolyte side" (for example, only electrolyte solution is added), and the other side is used as the "analyte side" (adding the analyte or the solution containing the analyte), and the solid-state nanopore is used in the middle to exchange substances or signals. In this embodiment, the response of the nanopore sensor under different concentrations of Cu-EDTA solutions is studied, and the solution concentration is changed on the "electrolyte side" or "analyte side", that is, 0.6mol / L, 0.8mol / L, 1mol / L, 1.2mol / L and other concentrations of Cu-EDTA are added to the groove on this side; while the other side (which may be the control side) maintains 0mol / L of Cu-EDTA or keeps pure electrolyte.

[0060] By applying a voltage of 110 mV on both sides of the solid-state nanopore of the device, the Cu-EDTA complex molecules are allowed to pass through the nanopore. The current change in this process is affected by the blocking effect of the complex, forming a translocation signal. The electric field of the electrodes in the fluid pool and the nanopore drives the Cu-EDTA molecules through the pore, resulting in a change in the current amplitude.

[0061] The current changes (blocking current amplitude ΔI) and translocation time Δt when passing through the nanopore are monitored and recorded in real time, and the data are recorded by a patch clamp amplifier and signal acquisition system connected to a computer.

[0062] According to the measured IV current-voltage curve, the Cu-EDTA concentration was calculated using the fitting method. The current characteristics and translocation signals of Cu-EDTA solutions with different concentrations were obtained through statistical analysis of the current amplitude and translocation time. Figure 3 shown.

[0063] The concentration of the Cu-EDTA sample to be detected is determined by comparing the translocation signal of the standard concentration solution with the signal of the actual sample solution.

[0064] The waste liquid formed after the nanopore detection is absorbed by the absorption layer of the device.

[0065] Solid-state nanopores are thin film structures with nanoscale pores. By precisely controlling the pore size and surface chemical properties, selective recognition and detection of specific molecules or complexes can be achieved. When the Cu-EDTA complex passes through the nanopore, a short current blocking signal is generated in the pore due to its volume, charge and shape characteristics. By recording the amplitude, duration and frequency of these blocking signals, the concentration, size distribution and movement behavior of the Cu-EDTA complex can be obtained.

[0066] Solid-state nanopore detection is based on the principle of resistive pulse sensing. When charged particles in a solution (such as Cu-EDTA complex) pass through a nanopore driven by an electric field, they temporarily partially block the flow of ions in the pore, causing an instantaneous change in the detection current. This current change directly reflects the physicochemical properties of the particles (such as size, charge, and shape). By analyzing these properties, highly sensitive quantitative detection of the target complex can be achieved. Compared with traditional sensors, solid-state nanopores not only have high stability and long life, but can also adapt to complex environmental conditions, and have good compatibility with microfluidics and semiconductor technologies, which facilitates miniaturization and mass production.

[0067] Combined with resistive pulse sensing technology, the solid-state nanopore sensor can monitor the concentration changes of Cu-EDTA complex in real time, providing high-sensitivity and high-precision technical support for dynamic monitoring of environmental pollution. This technological breakthrough provides a new method for accurate detection of heavy metal pollution, and is expected to promote the comprehensive improvement of online monitoring of pollutants and environmental risk assessment.

[0068] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A Cu-EDTA detection device based on solid-state nanopore detection technology, characterized in that: include: Fluid pool, solid-state nanopore sensor, voltage application device, signal acquisition system, data processing unit; The solid-state nanopore sensor is installed in the middle of the fluid pool; A voltage applying device, used to apply a stable voltage on both sides of the nanopore of the solid-state nanopore sensor to drive the Cu-EDTA molecules to pass through the nanopore; A signal acquisition system, used to obtain current signals; A data processing unit is used to obtain the concentration of Cu-EDTA according to the current signal.

2. The Cu-EDTA detection device based on solid-state nanopore detection technology according to claim 1, characterized in that: The nanopore of the solid-state nanopore sensor has a pore diameter of 1.5 nm.

3. The Cu-EDTA detection device based on solid-state nanopore detection technology according to claim 1, characterized in that: Grooves are provided on both sides of the fluid pool, and guide holes are provided in the grooves. The positive electrode and the negative electrode of the voltage applying device are respectively inserted into the guide holes on both sides of the fluid pool.

4. A Cu-EDTA detection method based on the solid-state nanopore detection technology based on the device according to any one of claims 1 to 3, characterized in that: include: Prepare electrolyte solution; obtain the object to be tested, and prepare standard Cu-EDTA solutions of different concentrations based on the object to be tested; adding the electrolyte solution and the standard Cu-EDTA solution to both sides of the solid-state nanopore sensor in the fluid cell respectively; A stable voltage is applied to both sides of the nanopore of the solid-state nanopore sensor, a current signal is acquired through a signal acquisition system, and the concentration of Cu-EDTA is obtained based on the current signal analysis.

5. The Cu-EDTA detection method based on solid-state nanopore detection technology according to claim 4, characterized in that: The electrolyte solution is a mixture of ammonia water and methanol, and the pH range of the electrolyte solution is 9.5-11.

5.

6. The Cu-EDTA detection method based on solid-state nanopore detection technology according to claim 4, characterized in that: The process of obtaining the object to be tested includes: After the tailings are collected, they are naturally air-dried and crushed, 0.01-0.02 g of the sample is weighed, and leached by vibration at a solid-liquid ratio of 10:1, and the leachate is used as the test object.

7. The Cu-EDTA detection method based on solid-state nanopore detection technology according to claim 4, characterized in that: The standard Cu-EDTA solution includes four concentrations: 0.6 mol / L, 0.8 mol / L, 1 mol / L and 1.2 mol / L.

8. The Cu-EDTA detection method based on solid-state nanopore detection technology according to claim 4, characterized in that: The stable voltage is 110 mV.

9. The Cu-EDTA detection method based on solid-state nanopore detection technology according to claim 4, characterized in that: The process of obtaining the concentration of Cu-EDTA includes: analyzing the amplitude change and translocation time of the current signal, performing statistical analysis on the amplitude change and the translocation time, and obtaining the current characteristics and translocation signals of standard Cu-EDTA solutions of different concentrations; and obtaining the Cu-EDTA concentration of the Cu-EDTA complex solution to be detected based on the current characteristics and translocation signals of the standard Cu-EDTA solutions of different concentrations.

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