Copper ferrocyanide / copper benzene hexathiol electrode material, preparation method and application thereof
By combining copper ferrocyanide/copper hexathiophenol composite nanomaterials with conductive MOFs to construct a molecularly imprinted electrochemical sensor, the problem of insufficient sensitivity in the detection of medazone and EDDP in complex environmental matrices was solved, achieving trace detection with high selectivity and high sensitivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INNOVATION CENTER OF YANGTZE RIVER DELTA ZHEJIANG UNIVERSITY
- Filing Date
- 2025-08-22
- Publication Date
- 2026-07-21
Smart Images
Figure CN121186153B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electroanalytical chemical detection and preparation technology of composite nanomaterials, and particularly relates to an electrochemical sensing composite nanomaterial with built-in redox probe copper ferrocyanide / copper hexathiophenol and its application. Background Technology
[0002] Methadone is a synthetic opioid widely used for the relief of chronic pain and opioid replacement therapy. However, due to its addictive nature, it is subject to abuse, overuse, illegal distribution, and indiscriminate discharge, increasingly posing serious public health risks and environmental pollution hazards. Methadone and its main biometabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), are prevalent in urban wastewater and have become typical emerging organic pollutants. Because existing wastewater treatment processes have low removal efficiency for methadone (<40%), it and its metabolites are discharged into natural water bodies, posing a potential threat to ecological health. EDDP, as a stable metabolite of methadone, is often used as a biomarker in wastewater epidemiological studies to reflect regional drug use trends. Therefore, the detection of methadone and its metabolites in municipal wastewater and surface water not only has environmental monitoring significance but also provides key technical support for drug control.
[0003] Currently, the detection of methadone and EDDP in wastewater and surface water faces significant technical bottlenecks: their concentrations in wastewater and surface water are in the ng / L range. While mature detection techniques such as liquid chromatography-tandem mass spectrometry (LC-MS / MS) offer high sensitivity, the instruments are expensive, the operation is complex, and sample preparation is cumbersome, making them unsuitable for rapid on-site detection. Existing portable devices (such as colorimetric test strips, handheld Raman / infrared spectrometers, and fluorescence spectrometers) can be used for high-concentration sample analysis, but their sensitivity is insufficient and their anti-interference capabilities are poor in trace detection under complex matrix conditions. Electrochemical sensing technology, due to its portability, rapid response, and high sensitivity, has broad application prospects in trace pollutant detection. Methadone, as an electroactive compound, can undergo oxidation reactions on electrodes modified with nanomaterials. Studies have shown that carbon-based nanomaterials can enhance its electrochemical response in biological samples. However, such electrocatalytically based methods struggle to achieve highly sensitive detection of methadone concentrations in the ng / L range in complex environmental matrices, limiting their application in environmental water bodies. Therefore, there is an urgent need to develop a detection technology with high sensitivity and selectivity to achieve efficient detection of medazone and EDDP in wastewater and surface water.
[0004] Electrochemical sensing combined with molecularly imprinted polymers (MIPs) can enhance the detection capability of trace analytes through selective adsorption, achieving highly sensitive and selective detection of substances. By introducing redox probes, MIP sensors can utilize the current change induced by the binding of the target analyte to the imprinted site to achieve indirect detection; this strategy is applicable to various types of target analytes (Li et al, Biosensors and Bioelectronics, 2024, 249:116018). Prussian blue analogues (PBAs) have been used as built-in redox probes, synergistically improving imprinting efficiency and detection performance with high surface area materials. Conductive metal-organic frameworks (MOFs) synthesized through a template sacrifice strategy not only retain their porous structure but also provide ample electron transport channels and reactive sites, making them ideal carriers for constructing high-performance surface molecularly imprinted electrode materials. Currently, there are no publicly reported applications of combining PBAs with conductive MOF materials to construct electrochemical sensors. Constructing electrochemical sensing materials with highly sensitive, selective, and stable redox probes is of great significance for the on-site detection of low-concentration substances in complex aquatic environments. Summary of the Invention
[0005] The purpose of this invention is to address the insufficient sensitivity of electrochemical detection techniques for methadone and EDDP at concentrations of ng / L by providing a sensing electrode material made of copper ferrocyanide / copper hexathiophenol composite material, its preparation method, and its applications.
[0006] The objective of this invention is achieved through the following technical solution:
[0007] In a first aspect, a copper ferrocyanide / copper hexathiophenol electrode material is provided. The copper ferrocyanide / copper hexathiophenol composite nanomaterial is composed of a conductive MOF copper hexathiophenol and a built-in redox probe copper ferrocyanide. The copper ferrocyanide is a Prussian blue analogue that is fixed on the surface of copper hexathiophenol by in-situ bonding and has good conductivity and stable reversible redox properties.
[0008] Secondly, a method for preparing the aforementioned copper ferrocyanide / copper hexathiophenol electrode material is provided, comprising the following steps:
[0009] The precursor HKUST-1MOF was synthesized by coordination reaction between a copper ion source and triethylammonium salt of 1,3,5-benzenetricarboxylic acid. A copper-benzenehexylthiophenol MOF material was generated by ligand exchange reaction between benzenehexylthiophenol and the precursor HKUST-1MOF. Utilizing the abundant metal sites of the copper-benzenehexylthiophenol MOF material, it was reacted with potassium ferrocyanide and potassium ferrocyanide to generate and fix copper ferrocyanide in situ through coordination bonding. After drying, the copper ferrocyanide / copper-benzenehexylthiophenol composite nanomaterial was obtained.
[0010] In some implementations, the method specifically includes the following steps:
[0011] (1) Add 1.5 mL of copper nitrate solution with a concentration of 0.08–0.12 mol / L (preferably 0.1 mol / L) to 240 mL of ethanol-water mixed solution, wherein the volume ratio of ethanol to water is (0.8–1):1 (preferably 1:1). After stirring and dissolving, add 1 mL of 1,3,5-benzenetricarboxylic acid triethylammonium salt aqueous solution with a concentration of 0.1–0.15 mol / L (preferably 0.1 mol / L). Stir the reaction for 5–10 min. After centrifugation and washing with deionized water, the reaction solution is vacuum dried at 50–70 °C for 8–24 h to obtain the precursor HKUST-1MOF of copper phenylhexathiophenol MOF.
[0012] (2) Disperse 30 mg HKUST-1 MOF obtained in step (1) in 16 mL of deoxymethanol; add 8 mL of benzene hexathiophenol deoxymethanol solution with a concentration of 3.5–5 mmol / L (preferably 4 mmol / L) and stir the reaction at room temperature for 5 h; after the reaction is completed, the product is separated by centrifugation, washed and dried under vacuum at 50–70 °C for 8–24 h to obtain copper benzene hexathiophenol MOF material;
[0013] (3) Disperse the 30 mg copper benzene hexathiophenol MOF obtained in step (2) in 75 mL of a mixed solution consisting of N,N-dimethylformamide (DMF), 30% hydrogen peroxide (H2O2) and deionized water, wherein the volume ratio of DMF:30% H2O2:water is (6-8):(1-2):3, preferably 6:1:3; add 2-6 mmol of potassium ferrocyanide and potassium ferrocyanide in a molar ratio of 1:1 to the mixed solution, stir and react at room temperature for 12 h, and centrifuge, wash and dry the product under vacuum at 50-70 °C for 8-24 h to obtain copper ferrocyanide / copper benzene hexathiophenol composite nanomaterials.
[0014] Thirdly, the copper ferrocyanide / copper hexathiophenol electrode material is further improved for preparing a molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode for recognizing methadone and EDDP. The preparation method includes the following steps:
[0015] (1) Copper ferrocyanide / copper hexathiophenol was added to an isopropanol and water dispersion containing Nafion solution and uniformly drop-coated onto the surface of a screen-printed carbon working electrode to obtain a copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode with a loading of 0.2 mg / cm³. 2 ;
[0016] (2) A 60 μL H2SO4 solution containing methadone and para-aminobenzoic acid was used as the electrolyte, wherein the molar ratio of para-aminobenzoic acid to methadone was (6-7):1, preferably 6:1, the concentration of para-aminobenzoic acid was 2-4 mmol / L, preferably 3 mmol / L, and the concentration of H2SO4 was 0.1 mol / L. Electrochemical cyclic voltammetry was used to polymerize the methadone-containing polymer / copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode, with a voltage range of -0.2–1.2 V and a scan rate of 50 mV·s. -1 The number of aggregation circles is 5;
[0017] (3) Elution of template molecules: 60 μL of methanol aqueous solution (66.7 vol%) was added dropwise to the polymer / copper ferrocyanide / copper hexathiophenol / screen printed electrode obtained in step (2) to elute methadone. The elution time was 1-1.5 min. The eluted electrode was washed with deionized water and dried at 25 °C to obtain molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen printed carbon electrode.
[0018] Fourthly, the aforementioned molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode can be used to construct an electrochemical sensor for detecting methadone and its main metabolite EDDP in water. Specifically, the molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode serves as the working electrode, while the carbon electrode and Ag / AgCl electrode serve as the counter and reference electrodes, respectively. Differential pulse voltammetry is used for determination; by measuring the change in the voltammetric peak current before and after adsorption of the target substance, quantitative analysis of methadone and its metabolites is achieved.
[0019] The beneficial effects of this invention are that the copper ferrocyanide / copper hexathiophenol composite material prepared by this invention has both excellent conductivity and stable built-in redox probe, which can serve as an efficient carrier for molecularly imprinted electrochemical sensors, significantly improving detection sensitivity and enabling accurate detection of ng / L methadone and its metabolite EDDP. It is suitable for drug monitoring in wastewater epidemiology and trace analysis of environmental pollutants, and has good practical application prospects. Attached Figure Description
[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments;
[0021] Figure 1 The following are the (a) XRD and (b) Raman spectra of the precursors HKUST-1, copper hexathiophenol, and copper ferrocyanide / copper hexathiophenol-3 in Example 1 of the present invention.
[0022] Figure 2 SEM images of (a) HKUST-1 and (b) copper hexathiophenol in Example 1;
[0023] Figure 3 The electrochemical performance of copper ferrocyanide / copper hexathiophenol in Example 1 is shown in Figure 1. (a) is the CV curve of the electrodes prepared by copper hexathiophenol, copper ferrocyanide / copper hexathiophenol-1, copper ferrocyanide / copper hexathiophenol-2 and copper ferrocyanide / copper hexathiophenol-3 in 0.1 mol / L KCl aqueous electrolyte, and (b) is the CV curve of the copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode after 80 cycles of testing.
[0024] Figure 4 SEM images of the molecularly imprinted / copper ferrocyanide / copper hexathiophenol in Example 2; (a) scale bar is 300 nm, (b) scale bar is 100 nm;
[0025] Figure 5 The following are the signal response diagrams of the sensor in Example 2: (a) is a schematic diagram of the sensor's signal response; (b) is a DPV diagram of the sensor after adsorbing different concentrations of EDDP; and (c) is a standard curve showing the change of the response signal ΔI with the lg value of methadone and EDDP concentrations.
[0026] Figure 6 The graph shows the test results of (a) anti-interference and (b) stability of the sensor in Example 2. Detailed Implementation
[0027] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.
[0028] Example 1
[0029] The preparation and electrochemical characterization of a copper ferrocyanide / copper hexathiophenol electrode material includes the following steps:
[0030] (1) 1.5 mL of 0.1 mol / L copper nitrate solution was added to 240 mL of ethanol-water mixed solution (ethanol to water volume ratio of 1:1). After stirring and dissolving, 1 mL of 0.1 mol / L triethylammonium salt of 1,3,5-benzenetricarboxylic acid (synthesis method is described in Liu et al, CrystEngComm, 2016, 18, 4127-4132) aqueous solution was added. The reaction was stirred for 6 min. After centrifugation and washing with deionized water, the reaction solution was dried under vacuum at 60 °C for 8 h to obtain the precursor HKUST-1MOF of copper benzene hexathiophenol MOF.
[0031] (2) Disperse 30 mg HKUST-1 MOF obtained in step (1) in 16 mL of deoxyethanol; add 8 mL of 4 mmol / L benzene hexathiophenol deoxyethanol solution to it, stir and react for 5 h at room temperature; after the reaction is completed, the product is separated by centrifugation, washed, and vacuum dried at 60 °C for 8 h to obtain copper benzene hexathiophenol MOF material.
[0032] (3) Disperse the 30 mg copper benzene hexathiophenol MOF obtained in step (2) in a 75 mL mixed solution composed of DMF, 30% H2O2 and deionized water, wherein the volume ratio of DMF: 30% H2O2: water is 6:1:3; add 2, 4 and 6 mmol of potassium ferrocyanide and potassium ferrocyanide to the mixed solution respectively, with a molar ratio of 1:1, stir and react at room temperature for 12 h, and the resulting product is centrifuged, washed and dried under vacuum at 60 °C for 8 h to obtain copper ferrocyanide / copper benzene hexathiophenol composite nanomaterials, which are named copper ferrocyanide / copper benzene hexathiophenol-1, copper ferrocyanide / copper benzene hexathiophenol-2 and copper ferrocyanide / copper benzene hexathiophenol-3.
[0033] (4) 2.5 mg of copper ferrocyanide / copper hexathiophenol was added to 1 mL of a 50 vol% isopropanol aqueous solution containing 0.1 wt.% Nafion, and then uniformly drop-coated onto the surface of a screen-printed carbon working electrode to obtain a copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode with a loading of 0.2 mg / cm³. 2 .
[0034] Figure 1 The XRD and Raman spectra of precursors HKUST-1, copper hexathiophenol, and copper ferrocyanide / copper hexathiophenol-3 are shown. Their characteristic peaks indicate successful preparation of HKUST-1, copper hexathiophenol, and copper ferrocyanide / copper hexathiophenol-3. After the formation of copper ferrocyanide / copper hexathiophenol-3, the Raman spectrum retains the characteristic peak of copper hexathiophenol, and the peak is located at 2111.5 cm⁻¹. -1 A distinct Fe-C≡N stretching vibration peak was observed. Combined with the XRD results, the copper ferrocyanide / copper hexathiophenol composite structure retained the copper hexathiophenol structure, and the Cu element in copper hexathiophenol served as a Cu source in [Fe(CN)6]. 3– / 4– The bonds formed copper ferrocyanide.
[0035] Figure 2 The images show SEM images of HKUST-1 and copper hexathiophenol. HKUST-1 is a cube with a side length of 300 nm and a smooth surface. The copper hexathiophenol formed after the reaction also exhibits a cubic shape, consistent with the particle size of the precursor, and has a rough surface.
[0036] Figure 3Electrochemical cyclic voltammetry (CV) of copper ferrocyanide / copper hexathiophenol. (a) CV curves of electrodes prepared with copper hexathiophenol, copper ferrocyanide / copper hexathiophenol-1, copper ferrocyanide / copper hexathiophenol-2, and copper ferrocyanide / copper hexathiophenol-3 in 0.1 mol / L KCl aqueous electrolyte. Compared with copper hexathiophenol, copper ferrocyanide / copper hexathiophenol exhibits a pair of reversible redox peaks at 0.6 V. Furthermore, the CV peak current increases with increasing concentrations of potassium ferrocyanide and potassium ferrocyanide in the reaction, indicating that copper ferrocyanide / copper hexathiophenol-3 possesses good conductivity and reversible redox properties. (b) CV curve of the copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode after 80 cycles of testing. The CV curve almost overlaps with the initial CV curve, indicating stable electrochemical reversible redox properties.
[0037] Example 2
[0038] In Example 1, a molecularly imprinted / copper hexathiophenol / screen-printed carbon working electrode was prepared using a copper ferrocyanide / copper hexathiophenol-3 / screen-printed carbon working electrode. The specific steps are as follows:
[0039] (1) A 0.1 mol / L H2SO4 solution containing methadone and 3 mmol / L p-aminobenzoic acid was used as the electrolyte, with a molar ratio of p-aminobenzoic acid to methadone of 6:1. Electrochemical cyclic voltammetry was used for polymerization to obtain a polymer containing methadone / copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode with a voltage range of -0.2–1.2 V and a scan rate of 50 mV·s. -1 The number of aggregation circles is 5;
[0040] (2) 60 μL of methanol aqueous solution (66.7 vol%) was added dropwise to the polymer / copper ferrocyanide / copper hexathiophenol / screen printed electrode obtained in step 1 to elute the template molecule methadone for 1 min. The eluted electrode was washed with deionized water and dried at 25 °C to obtain the molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen printed carbon electrode.
[0041] An electrochemical sensor was constructed using a molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode as the working electrode, and an Ag / AgCl electrode as the counter electrode and reference electrode, respectively. A 60 μL solution of 0.1 mol / L KCl was used as the electrolyte. The peak current difference ΔI before and after adsorption of medazine or EDDP in the water was measured by differential pulse voltammetry. ΔI showed a two-segment linear correlation with lgC.
[0042] Figure 4The image shows a SEM image of molecularly imprinted copper ferrocyanide / copper hexathiophenol. Some parts of the image exhibit a complete cubic structure, while others show pores on their surface. This may be due to the localized consumption of copper hexathiophenol, which leads to the partial loss of copper ferrocyanide / copper hexathiophenol. The detached copper ferrocyanide / copper hexathiophenol then forms a loose, porous structure composed of granules.
[0043] Figure 5 This is the signal response graph of the sensor. As the adsorbed EDDP concentration increases, the DPV peak current decreases, and the methadone concentration C ranges from 10... -9 -10 -3 mol / L, detection limit is 10.6 × 10⁻⁶ -12 mol / L, or 3.28 ng / L; the concentration C of EDDP is in the range of 10 mol / L. -11 -10 -3 mol / L, detection limit is 3.6 × 10⁻⁶ -13 The concentration is mol / L, or 99.86 pg / L. This indicates that the electrochemical sensor has high sensitivity for the detection of methadone and EDDP.
[0044] Figure 6 The sensor's anti-interference and stability were demonstrated. Interference tests were conducted using hydrochloric acid (HCl), sodium hydroxide (NaOH), potassium chloride (KCl), sodium sulfate (Na2SO4), humic acid, glucose, sodium dodecylbenzenesulfonate (SDBS), and diatomite. When the concentration of the interfering agent was 10 times that of the target analyte (HCl, NaOH, KCl, Na2SO4, glucose, and SDBS: 100 μM; humic acid and diatomite: 1 g / L; methadone and EDDP: 10 μM), the response current significantly increased in the presence of methadone or EDDP, indicating good specificity for methadone and EDDP. The electrode was vacuum-preserved at room temperature, and the electrochemical response signal of the sensor to EDDP was recorded over 7 weeks. The RSD was 1.30%, demonstrating the sensor's good stability.
[0045] Example 3: Performance Evaluation of Electrochemical Sensor
[0046] To evaluate the sensor's performance in practical applications, actual water samples from municipal wastewater treatment plants and rivers were selected, and the samples filtered through 0.45 μm glass fiber membranes were tested. The detection results of EDDP and methadone-spiked samples are summarized in Table 1.
[0047] Table 1. Detection results of EDDP and methadone in domestic sewage and river water
[0048]
[0049] For filtered wastewater and river water samples, the recoveries of EDDP were 104.5% and 102.0%, respectively, with relative standard deviations (RSDs) below 5.0%. In contrast, the recoveries of methadone were 110.5% and 103.0%, respectively, with RSDs also below 5.0%. These results indicate that, under conditions of reduced matrix interference, the sensor exhibits high detection accuracy and repeatability, demonstrating potential for practical applications.
Claims
1. A copper ferrocyanide / copper hexathiophenol electrode material, characterized in that, The copper ferrocyanide / copper hexathiophenol electrode material is composed of a conductive metal-organic framework and an embedded redox probe. The conductive metal-organic framework is copper hexathiophenol, and the embedded redox probe is copper ferrocyanide. The copper ferrocyanide is fixed on the surface of copper hexathiophenol by in-situ bonding. The precursor HKUST-1 MOF was prepared by the following steps: a coordination reaction was carried out between a copper ion source and triethylammonium salt of 1,3,5-benzenetricarboxylic acid to synthesize HKUST-1 MOF; a ligand exchange reaction was carried out between phenylhexathiophenol and the precursor HKUST-1 MOF to generate copper phenylhexathiophenol MOF material; the copper phenylhexathiophenol MOF material was reacted with potassium ferrocyanide and potassium ferrocyanide to generate and fix copper ferrocyanide in situ through coordination bonding, and then dried to obtain copper ferrocyanide / copper phenylhexathiophenol composite nanomaterial.
2. The copper ferrocyanide / copper hexathiophenol electrode material according to claim 1, characterized in that, The coordination reaction via a copper ion source and triethylammonium 1,3,5-benzenetricarboxylate includes the following steps: 1.5 mL of a 0.08–0.12 mol / L copper nitrate solution is added to 240 mL of an ethanol-water mixture, wherein the volume ratio of ethanol to water is (0.8–1):
1. After stirring to dissolve, 1 mL of a 0.1–0.15 mol / L aqueous solution of triethylammonium 1,3,5-benzenetricarboxylate is added. The mixture is stirred for 5–10 min, and the reaction solution is centrifuged, washed, and dried.
3. The copper ferrocyanide / copper hexathiophenol electrode material according to claim 1, characterized in that, The ligand exchange reaction using benzene hexathiophenol and the precursor HKUST-1 MOF includes the following steps: 30 mg of HKUST-1 MOF is dispersed in 16 mL of deoxymethanol; 8 mL of benzene hexathiophenol deoxymethanol solution with a concentration of 3.5–5 mmol / L is added to the solution, and the mixture is stirred at room temperature for 5 h; after the reaction is completed, the product is centrifuged, washed, and dried.
4. The copper ferrocyanide / copper hexathiophenol electrode material according to claim 1, characterized in that, The copper phenylhexathiophenol MOF material reacts with potassium ferricyanide and potassium ferrocyanide to generate and fix copper ferrocyanide in situ through coordination bonding, including the following steps: 30 mg of copper phenylhexathiophenol MOF is dispersed in 75 mL of a mixed solution composed of DMF, 30% H2O2 and water, wherein the volume ratio of DMF:30% H2O2:water is (6-8):(1–2):3; 2–6 mmol of potassium ferricyanide and potassium ferrocyanide are added to the mixed solution in a molar ratio of 1:1, and the mixture is stirred at room temperature for 12 h. The resulting product is then centrifuged, washed, and dried.
5. The copper ferrocyanide / copper hexathiophenol electrode material according to any one of claims 1-4, characterized in that, The drying process is as follows: vacuum drying at 50–70°C for 8–24 hours.
6. A molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode for identifying methadone and EDDP, characterized in that, It is prepared through the following steps: (1) The copper ferrocyanide / copper hexathiophenol electrode material of claim 1 was added to a Nafion dispersion and uniformly drop-coated onto the surface of a screen-printed carbon electrode to obtain a copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode with a loading of 0.2 mg / cm³. 2 ; (2) Using an H2SO4 solution containing methadone and para-aminobenzoic acid as the electrolyte, polymerization was carried out by electrochemical cyclic voltammetry to obtain a polymer containing methadone / copper ferrocyanide / copper hexathiophenol / screen-printed carbon working electrode with a voltage range of -0.2–1.2 V and a scan rate of 50 mV·s. −1 The number of aggregation circles is 5; (3) Elute the template molecules, wash the eluted electrode with water, and dry it to obtain a molecularly imprinted / copper ferrocyanide / copper benzene hexathiophenol / screen printed carbon electrode.
7. The molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode according to claim 6, characterized in that, In step (2), the molar ratio of para-aminobenzoic acid to methadone is (6-7):1, the concentration of para-aminobenzoic acid is 2-4 mmol / L, and the concentration of H2SO4 is 0.1 mol / L.
8. The molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode according to claim 6, characterized in that, In step (3), 60 μL of a 66.7 vol% methanol-water eluent is added dropwise to the obtained polymer / copper ferrocyanide / copper hexathiophenol / screen-printed electrode to elute methadone for 1-1.5 min; the drying is carried out at 25°C. o Perform under C.
9. The use of the molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode of claim 6 in the identification of methadone and EDDP, characterized in that, Using a molecularly imprinted / copper ferrocyanide / copper hexathiophenol / screen-printed carbon electrode as the working electrode, and an Ag / AgCl electrode as the counter electrode and reference electrode, differential pulse voltammetry was employed to quantitatively determine medazone and its metabolite EDDP in domestic sewage and river water.