Electrochemical SERS dual-mode sensor based on wearable flexible gloves and its preparation and application

Abstract

The present invention relates to the technical field of pesticide molecule detection, and in particular to an electrochemical SERS dual-mode sensor based on wearable flexible gloves, and its preparation and application. The present invention provides a wearable flexible glove, on which a flexible three-electrode is printed, mainly using AuNPs / GO / PDMS flexible material as a working electrode and a counter electrode, and Ag / AgCl ink as a reference electrode, to form a flexible three-electrode system. An electrochemical enrichment method is adopted to immerse the sensing finger in a water sample to adsorb pesticide molecules in the solution, and then a handheld Raman spectrometer is used to perform SERS detection on the substance on the surface of the flexible three electrodes to obtain the Raman spectrum signal of the pesticide, thereby performing quantitative analysis and detection on the pesticide molecules. The present invention has the advantages of high sensitivity, small sample volume, wide linear range, short response time, etc., and can therefore be widely used in aspects such as drug analysis and environmental monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide molecule detection, and in particular to an electrochemical SERS dual-mode sensor based on wearable flexible gloves, and the preparation and application thereof. Background Art

[0002] Pesticides are synthetic or natural compounds or mixtures used to control, eliminate, regulate, prevent, or repel diseases, weeds, insects, and pests that affect plant growth. These compounds are generally classified based on their chemical structure, mode of action, degree of hazard, method of application, and timing of application. Agricultural crop yields have increased significantly over the past few decades due to the introduction of chemical pesticides. Pesticide residues can enter the food chain through fruits, vegetables, processed foods, water, air, and soil. Dietary exposure to agricultural pesticides can cause acute and chronic health effects in humans, making it a significant public health concern. Chemical pesticides can have cytotoxic, mutagenic, and carcinogenic effects on human health. Simazine (Sim) is a low-toxic, highly effective triazine herbicide widely used worldwide to effectively control annual broadleaf weeds and grasses. However, due to its low solubility in water, long-lasting residual effect, difficulty in biodegradation, and high ecotoxicity, simazine has become one of the most significant environmental pollutants. Malathion (Mal) is an organophosphorus chemical pesticide that can remain in agricultural products, causing irreversible adverse effects on human health.

[0003] Traditional analytical techniques for pesticide detection include gas chromatography (GC), liquid chromatography (LC), high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC–MS), liquid chromatography-mass spectrometry (LC-MS), micellar electrokinetic capillary chromatography, and capillary electrophoresis (CE). Although these methods are highly specific, exhibiting significant selectivity and sensitivity, some limitations include the need for sophisticated laboratory equipment and specialized trained technicians, expensive instrumentation, complex operation, high analytical costs, and time-consuming procedures. Furthermore, these complex analytical techniques require tedious sample preparation, pretreatment, and preconcentration protocols prior to studying trace pesticides in various food and environmental samples. Therefore, it is crucial to provide a pesticide detection method that is rapid, sensitive, and selective. Summary of the Invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide an electrochemical SERS dual-mode sensor based on wearable flexible gloves and its preparation and application.

[0005] Surface-enhanced Raman scattering (SERS) technology offers the advantages of excellent non-destructive detection, extremely high analytical sensitivity, and extremely short detection time, making it an effective means for rapid and non-destructive detection of trace pollutants. As an indispensable component of this technology, the development of functional SERS substrates is of great significance for promoting the practical application of SERS technology. Among them, flexible SERS substrates, due to their deformable properties, can highly conform to pollutants on surfaces of varying morphologies and roughness for sampling, and have broad application prospects in the field of non-destructive, sensitive, rapid, and on-site detection of pesticide pollutants. At the same time, electrostatic forces enable the SERS substrate to enrich pesticide molecules around its "hotspot" region, thereby inducing charge transfer and subsequently enhancing its Raman signal.

[0006] Simazine is positively charged in aqueous solution, while malathion is negatively charged. Electrochemical in situ enrichment can selectively adsorb simazine and malathion, enabling rapid on-site detection of pesticide molecules. Electrochemical enrichment-SERS technology offers rapid analysis, high sensitivity, and excellent selectivity, and is expected to be further applied in environmental and food analysis and testing.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The first object of the present invention is to provide a method for preparing an electrochemical SERS dual-mode sensor based on a wearable flexible glove, comprising the following steps:

[0009] (1) Design a flat finger mold using SolidWorks 3D CAD and print it using a Mojo 3D printer to obtain a finger mold;

[0010] (2) Designing a sensor pattern on the index finger of the finger mold prepared in step (1) using AutoCAD;

[0011] (3) Using a semi-automatic screen printer, the reference electrode, counter electrode, and working electrode were printed on the index finger of the finger mold in sequence according to the sensor pattern prepared in step (2), thereby obtaining an electrochemical SERS dual-mode sensor based on a wearable flexible glove.

[0012] In one embodiment of the present invention, in step (1), the finger mold has a size of 10.0×2.3×1.3 cm 3 .

[0013] In one embodiment of the present invention, in step (2), the sensor pattern is a flower-shaped pattern.

[0014] In one embodiment of the present invention, in step (3), the reference electrode is Ag / AgCl ink.

[0015] In one embodiment of the present invention, in step (3), the counter electrode and the working electrode are both AuNPs / GO / PDMS flexible electrodes.

[0016] In one embodiment of the present invention, in the AuNPs / GO / PDMS flexible electrode, polydimethylsiloxane (PDMS) is a flexible substrate, graphene oxide (GO) is a conductive layer, gold nanoparticles (AuNPs) are an electrochemically deposited layer, and AuNPs are deposited on GO.

[0017] The second object of the present invention is to provide an electrochemical SERS dual-mode sensor based on a wearable flexible glove prepared by the above method.

[0018] The third object of the present invention is to provide an application of an electrochemical SERS dual-mode sensor based on a wearable flexible glove in pesticide detection, comprising the following steps:

[0019] (A) The electrochemical SERS dual-mode sensor based on a wearable flexible glove is connected to a handheld micropotentiostat via a ring bandage.

[0020] Mix the PBS solution with the pesticide molecule solution to obtain standard pesticide reaction solutions with different concentrations;

[0021] Mixing the PBS solution with the sample to be tested to obtain a reaction solution to be tested;

[0022] (B) The electrochemical SERS dual-mode sensor based on the wearable flexible glove was immersed in standard pesticide reaction solutions of different concentrations and enriched using a handheld micro-potentiostat. After removal, the Raman signal of the pesticide molecules was detected using a handheld Raman spectrometer. A standard curve was plotted with the Raman signal intensity of the pesticide molecules as the y-axis and the Log value of the standard pesticide reaction solutions of different concentrations as the abscissa.

[0023] (C) The electrochemical SERS dual-mode sensor based on the wearable flexible glove is immersed in the reaction solution to be tested and enriched using a handheld micro-constant voltage potentiostat. After being taken out, the Raman signal of the pesticide molecules in the reaction solution to be tested is detected using a handheld Raman spectrometer. The Raman signal intensity of the pesticide molecules in the reaction solution to be tested is substituted into the standard curve prepared in step (B) to obtain the concentration of the pesticide molecules in the reaction solution to be tested.

[0024] In one embodiment of the present invention, in step (A), the pesticide molecule is selected from one of simazine and malathion.

[0025] In one embodiment of the present invention, when the pesticide molecule is simazine, during the enrichment process, the enrichment potential is -0.2 V and the enrichment time is 30 s.

[0026] In one embodiment of the present invention, when the pesticide molecule is malathion, during the enrichment process, the enrichment potential is +0.2 V and the enrichment time is 30 s.

[0027] In one embodiment of the present invention, during the Raman signal detection process, the excitation wavelength is 785 nm, the laser power is 80 mW, and the distance between the electrochemical SERS dual-mode sensor based on the wearable flexible glove and the handheld Raman spectrometer is maintained to ensure that a 1 mm laser spot is achieved on the electrochemical SERS dual-mode sensor based on the wearable flexible glove, and the excitation time is 10 s.

[0028] This paper designs an electrochemical-SERS dual-mode sensor based on a flexible wearable glove. This sensor utilizes a flexible AuNPs / GO / PDMS material as the working and counter electrodes, and an Ag / AgCl ink as the reference electrode, forming a flexible three-electrode system. This sensor employs an electrochemical enrichment method, immersing the sensing finger in a water sample to adsorb pesticide molecules from the solution. A handheld Raman spectrometer then performs SERS detection on the surface of the flexible three-electrode sensor, obtaining Raman spectral signals of the pesticide molecules and enabling quantitative analysis and detection. This sensor exhibits advantages such as high sensitivity, small sample volume, wide linear range, and short response time, making it suitable for a wide range of applications in pharmaceutical analysis and environmental monitoring.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The electrochemical SERS dual-mode sensor based on wearable flexible gloves designed in this invention has the advantages of highly stretchable screen-printed electrode system, miniaturization, implantability, portability, low cost, low energy consumption, high comfort, recyclability, degradability and good biocompatibility. It has good development prospects in the fields of medical equipment, clothing, aerospace and 3D printing.

[0031] (2) The AuNPs / GO / PDMS flexible SERS substrate material can effectively enrich pesticide molecules and produce a strong SERS response. PDMS is highly elastic, chemically stable, and cost-effective, and is more ductile than most common polymer elastomers. It can also be customized to achieve different functions through surface modification and overall properties, making PDMS the best choice for electrochemical SERS dual-mode sensors based on wearable flexible gloves. In addition, GO has been proven to be an efficient platform for exploring molecular enrichment surfaces; this allows GO to be flexibly combined with transparent PDMS, providing an option for the practical application of electrochemical SERS dual-mode sensors based on wearable flexible gloves. The entire preparation process of the present invention is fast and the preparation method is low-cost.

[0032] (3) The present invention combines electrochemical enrichment with SERS technology to simultaneously achieve the selective enrichment and detection of Sim and Mal in the sample to be tested. This method can not only eliminate the interference of other substances, but also improve the detection sensitivity of Sim and Mal.

[0033] (4) The present invention combines a handheld micropotentiostat with a handheld Raman spectrometer to achieve rapid on-site quantitative detection of Sim and Mal in test samples with good sensitivity, acceptable stability, and repeatability. The SERS detection limit for Sim is 0.003 nM, and the SERS detection limit for Mal is 0.0013 nM. This sensor is expected to become a new and effective method for on-site detection of pesticide molecules. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the flexible three-electrode screen printing process steps in the preparation of the electrochemical SERS dual-mode sensor based on wearable flexible gloves in Example 3;

[0035] Figure 2 The SERS spectrum changes of Sim before and after pre-enrichment of the electrochemical SERS dual-mode sensor based on wearable flexible gloves;

[0036] Figure 3 The SERS spectra of the electrochemical SERS dual-mode sensor based on wearable flexible gloves after incubation with different concentrations of Sim. The marks (dashed lines) shown in the figure are the characteristic peaks of Sim.

[0037] Figure 4 Standard curve diagram for Sim detection of electrochemical SERS dual-mode sensor based on wearable flexible gloves.

[0038] Figure 5 The SERS spectrum changes of Mal before and after pre-enrichment of the electrochemical SERS dual-mode sensor based on wearable flexible gloves;

[0039] Figure 6 The SERS spectra of the electrochemical SERS dual-mode sensor based on wearable flexible gloves after incubation with different concentrations of Mal. The marks (dashed lines) shown in the figure are the characteristic peaks of Mal.

[0040] Figure 7 Standard curve for detecting Mal using the electrochemical SERS dual-mode sensor based on wearable flexible gloves. DETAILED DESCRIPTION

[0041] The present invention provides a method for preparing an electrochemical SERS dual-mode sensor based on a wearable flexible glove, comprising the following steps:

[0042] (1) Design a flat finger mold using SolidWorks 3D CAD and print it using a Mojo 3D printer to obtain a finger mold;

[0043] (2) Designing a sensor pattern on the index finger of the finger mold prepared in step (1) using AutoCAD;

[0044] (3) Using a semi-automatic screen printer, the reference electrode, counter electrode, and working electrode were printed on the index finger of the finger mold in sequence according to the sensor pattern prepared in step (2), thereby obtaining an electrochemical SERS dual-mode sensor based on a wearable flexible glove.

[0045] In one embodiment of the present invention, in step (1), the finger mold has a size of 10.0×2.3×1.3 cm 3 .

[0046] In one embodiment of the present invention, in step (2), the sensor pattern is a flower-shaped pattern.

[0047] In one embodiment of the present invention, in step (3), the reference electrode is Ag / AgCl ink.

[0048] In one embodiment of the present invention, in step (3), the counter electrode and the working electrode are both AuNPs / GO / PDMS flexible electrodes.

[0049] In one embodiment of the present invention, in the AuNPs / GO / PDMS flexible electrode, PDMS is the flexible substrate, GO is the conductive layer, AuNPs is the electrochemically deposited layer, and AuNPs are deposited on GO.

[0050] The present invention provides an electrochemical SERS dual-mode sensor based on a wearable flexible glove prepared by the above method.

[0051] The present invention provides an application of an electrochemical SERS dual-mode sensor based on a wearable flexible glove in pesticide detection, comprising the following steps:

[0052] (A) The electrochemical SERS dual-mode sensor based on a wearable flexible glove is connected to a handheld micropotentiostat via a ring bandage.

[0053] Mix the PBS solution with the pesticide molecule solution to obtain standard pesticide reaction solutions with different concentrations;

[0054] Mixing the PBS solution with the sample to be tested to obtain a reaction solution to be tested;

[0055] (B) The electrochemical SERS dual-mode sensor based on the wearable flexible glove was immersed in standard pesticide reaction solutions of different concentrations and enriched using a handheld micro-potentiostat. After removal, the Raman signal of the pesticide molecules was detected using a handheld Raman spectrometer. A standard curve was plotted with the Raman signal intensity of the pesticide molecules as the y-axis and the Log value of the standard pesticide reaction solutions of different concentrations as the abscissa.

[0056] (C) The electrochemical SERS dual-mode sensor based on the wearable flexible glove is immersed in the reaction solution to be tested and enriched using a handheld micro-constant voltage potentiostat. After being taken out, the Raman signal of the pesticide molecules in the reaction solution to be tested is detected using a handheld Raman spectrometer. The Raman signal intensity of the pesticide molecules in the reaction solution to be tested is substituted into the standard curve prepared in step (B) to obtain the concentration of the pesticide molecules in the reaction solution to be tested.

[0057] In one embodiment of the present invention, in step (A), the pesticide molecule is selected from one of simazine and malathion.

[0058] In one embodiment of the present invention, when the pesticide molecule is simazine, during the enrichment process, the enrichment potential is -0.2 V and the enrichment time is 30 s.

[0059] In one embodiment of the present invention, when the pesticide molecule is malathion, during the enrichment process, the enrichment potential is +0.2 V and the enrichment time is 30 s.

[0060] In one embodiment of the present invention, during the Raman signal detection process, the excitation wavelength is 785 nm, the laser power is 80 mW, and the distance between the electrochemical SERS dual-mode sensor based on the wearable flexible glove and the handheld Raman spectrometer is maintained to ensure that a 1 mm laser spot is achieved on the electrochemical SERS dual-mode sensor based on the wearable flexible glove, and the excitation time is 10 s.

[0061] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] In the following examples, unless otherwise specified, all reagents used are commercially available reagents, and all detection means and methods used are conventional detection means and methods in the art.

[0063] Example 1

[0064] This embodiment provides an AuNPs / GO / PDMS flexible material and a preparation method thereof, comprising the following steps:

[0065] (1) Prepare a 0.1 mg / mL aqueous solution of graphene oxide, adjust the pH to 9-10, add vitamin C at a ratio of 2 mg / mL, and react at 95°C for 15 min; then adjust the concentration of the graphene solution reduced by vitamin C to 10 μm / mL, vacuum filter and dry to obtain a graphene film;

[0066] (2) The graphene film prepared in step (1) is transferred to the flexible polymer PDMS to obtain a graphene-PDMS hybrid composite film.

[0067] (3) Heat 100 mL of H2O and 1 mL of 0.01% HAuCl4 solution to boiling, then add 2.5 mL of 1% trisodium citrate, keep the solution boiling for 10 minutes, and then cool it to room temperature to obtain an AuNPs solution. At a potential of +0.2 V, use an electrochemical workstation to deposit gold nanoparticles on the surface of the graphene-PDMS hybrid composite film prepared in step (2). Finally, place it at room temperature to dry for one day to obtain an AuNPs / GO / PDMS flexible material.

[0068] Example 2

[0069] This embodiment provides an Ag / AgCl ink and a preparation method thereof, comprising the following steps:

[0070] Ag / AgCl ink was prepared by thoroughly mixing Ercon AgCl ink (9.5174 g) with Ecoflex 00-30 (1.443 g, 13.16 wt %) using a SpeedMixer (DAC 150.1 FVZ, FlackTek, Inc., Landrum, SC) for 5 min (2500 rpm).

[0071] The Ecoflex 00-30 used in this example was prepared by mixing equal volumes of prepolymer A and prepolymer B provided by a supplier.

[0072] Example 3

[0073] This embodiment provides an electrochemical SERS dual-mode sensor based on a wearable flexible glove and a preparation method thereof, comprising the following steps:

[0074] A semi-automatic MPM-SPM screen printer was used to fabricate disposable glove sensors. A 125 μm thick stainless steel template was designed and patterned with sensors using AutoCAD and laser cutting. To obtain a smooth and flat printing surface, a finger mold (10 × 2.3 × 1.3 cm) was drawn using SolidWorks 3D CAD. 3), and printed using a Mojo 3D printer.

[0075] Before screen printing the sensor structure, the 3D-printed finger mold was inserted into a purple nitrile glove. Figure 1 As shown, according to the sensor pattern, the Ag / AgCl ink prepared in Example 2 was printed on the index finger of the finger mold ( Figure 1 A in the figure) as the reference electrode and connection pad; the AuNPs / GO / PDMS flexible material prepared in Example 1 was printed on the index finger of the finger mold as the counter electrode ( Figure 1 B); the AuNPs / GO / PDMS flexible material prepared in Example 1 was again printed on the index finger of the finger mold as a working electrode ( Figure 1 C in); a flexible three-electrode system was prepared; and an electrochemical SERS dual-mode sensor based on a wearable flexible glove was obtained.

[0076] After printing each layer, it was cured at 85°C for 20 minutes.

[0077] Example 4

[0078] This example provides a method for determining the redox potential of simazine and malathion, comprising the following steps:

[0079] The electrochemical SERS dual-mode sensor based on the wearable flexible glove was connected to a handheld micro-potentiostat via a ring bandage. Cyclic voltammetry (CV) was performed using AuNPs / GO / PDMS flexible electrodes as working and counter electrodes and Ag / AgCl ink as the reference electrode.

[0080] a. Redox potential of Sim: 5mL 1×10 -4 The mixed solution of Sim and PBS with a concentration of mol / L was used as the electrolyte, and the scanning voltage was -1 to 0.2 V at a scanning rate of 50 mv / s to obtain the redox potential of Sim.

[0081] b. Redox potential of Mal: 5mL 1×10 -4 A mixed solution of mol / L Mal and PBS was used as the electrolyte, and the scanning voltage was 0.05-0.9 V at a scanning rate of 50 mV / s to obtain the redox potential of Mal;

[0082] According to the redox potentials of the above two pesticide molecules, the optimal enrichment potential of Sim is selected as -0.2V; the optimal enrichment potential of Mal is selected as +0.2V.

[0083] Example 5

[0084] This example provides the detection of Sim by the electrochemical SERS dual-mode sensor based on the wearable flexible glove prepared in Example 3, comprising the following steps:

[0085] (1) Mix 1 mL of Sim solution and 100 μL of 0.1 mol / L PBS (pH 7) solution to obtain Sim concentrations of 1.0×10 -7 M, 1.0×10 -6 M, 1.0×10 -5 M, 1.0×10 -4 M and 1.0×10 -3 M's standard Sim reaction solution.

[0086] (2) Wearing the flexible wearable gloves prepared in Example 3 for the sampling and detection steps, and connecting them to a handheld micro constant voltage potentiostat; immersing the sensing fingers in the reaction solutions of different concentrations prepared in step (1) for enrichment treatment, controlling the enrichment potential to -0.2 V, and the enrichment time to 30 s; after the enrichment treatment, taking the sensing fingers out of the reaction solution, and using a handheld Raman spectrometer to detect the Raman signal of Sim, with an excitation wavelength of 785 nm, a laser power of 80 mW, and an excitation time of 10 s; the resulting SERS response is wirelessly transmitted to a smart phone via the built-in wireless communication function of the handheld Raman spectrometer to obtain the SERS spectrum of the sample, thereby realizing SERS detection of Sim.

[0087] To avoid any cross contamination, each glove sensor is single-use.

[0088] like Figure 2 As shown in Figure 2, after electrochemical enrichment, the SERS intensity of Sim is significantly enhanced. The Raman spectrum peak at 1074 cm -1 and 1581 cm -1 As the characteristic peak for determining Sim, as the concentration of Sim gradually increases (1.0×10 -7 M~1.0×10 -3 M), 1074 cm in the Raman spectrum -1 and 1581 cm -1 The intensity of the characteristic peaks at the two locations gradually increases ( Figure 3 ), choose 1074 cm -1 and 1581 cm -1 The content of Sim can be calculated by combining the corresponding peak intensity with the linear curve. The Raman signal intensity of Sim is used as the ordinate and the Log value of the standard Sim reaction solution is used as the abscissa. The linear relationship between the concentration Log value of Sim and the Raman signal intensity is y=994.51x+14285.37, R 2 =0.9956( Figure 4 The detection limit (DL) was calculated based on the ratio of 3 times the standard deviation of the blank (δ) to the slope of the linear curve (k), that is, DL = 3δ / k, and the detection limit of Sim was 0.003 nM.

[0089] Example 6

[0090] This example provides the detection of Mal by the electrochemical SERS dual-mode sensor based on the wearable flexible glove prepared in Example 3, comprising the following steps:

[0091] (1) Mix 1 mL of Mal solution and 100 μL of 0.1 mol / L PBS (pH 7) solution to obtain Mal concentrations of 1.0×10 -7 M, 1.0×10 -6 M, 1.0×10 -5 M, 1.0×10 -4 M and 1.0×10 -3 M's standard Mal reaction solution.

[0092] (2) Wear the flexible wearable gloves prepared in Example 3 for the sampling and detection steps, and connect them to a handheld micro constant voltage potentiostat. Immerse the sensing fingers in the reaction solutions of different concentrations prepared in step (1) for enrichment treatment, control the enrichment potential to +0.2V, and the enrichment time to 30s. After the enrichment treatment, remove the sensing fingers from the reaction solution, and use a handheld Raman spectrometer to detect the Raman signal of Mal, with an excitation wavelength of 785nm, a laser power of 80mW, and an excitation time of 10s; the resulting SERS response is wirelessly transmitted to a smartphone via the built-in wireless communication function of the handheld Raman spectrometer to obtain the SERS spectrum of the sample, thereby achieving SERS detection of Mal.

[0093] To avoid any cross contamination, each glove sensor is single-use.

[0094] like Figure 5 As shown in Figure 2, after electrochemical enrichment, the SERS intensity of Mal is significantly enhanced. The Raman spectrum peak at 1146 cm -1 and 1435 cm -1 As the characteristic peak for determining Mal, as the concentration of Mal gradually increases (1.0×10 -7 M~1.0×10 -3 M), 1146 cm in the Raman spectrum -1 and 1435 cm -1 The intensity of the characteristic peaks at the two locations gradually increases ( Figure 6 ), select 1146 cm -1 and 1435 cm-1 The corresponding peak intensity can be combined with the linear curve to calculate the content of Mal. The Raman signal intensity of Mal is used as the ordinate and the Log value of the standard Mal reaction solution is used as the abscissa. The linear relationship between the concentration Log value of Mal and the Raman signal intensity is y=968.8x+18152.26, R 2 =0.9928( Figure 7 The detection limit (DL) was calculated based on the ratio of 3 times the standard deviation of the blank (δ) to the slope of the linear curve (k), that is, DL = 3δ / k. The detection limit of Mal was 0.0013 nM.

[0095] Example 7

[0096] This embodiment provides an application of an electrochemical SERS dual-mode sensor based on a wearable flexible glove to detect Sim and Mal in a water sample to be tested.

[0097] In this embodiment, the electrochemical SERS dual-mode sensor based on the wearable flexible glove prepared in Example 3 was used to detect Sim and Mal in the water sample to be tested, wherein the water sample to be tested was taken from the Bihai Jinsha waters in Shanghai.

[0098] (1) Mix 1 mL of the water sample to be tested with 1 mL of 5×10 -4 M standard Sim solution was mixed, and then mixed with 100 μL 0.1 mol / L PBS solution to obtain a first reaction solution. Then, the electrochemical SERS dual-mode sensor based on the wearable flexible glove was connected to a handheld micro constant voltage potentiostat, and the sensing finger was immersed in the reaction solution for enrichment treatment, and the enrichment potential was controlled to -0.2 V, and the enrichment time was 30 s. After the enrichment treatment, the sensing finger was removed from the reaction solution, and the Raman signal of Sim was detected using a handheld Raman spectrometer with an excitation wavelength of 785 nm, a laser power of 80 mW, and an excitation time of 10 s. The Raman intensity of Sim in the first reaction solution was obtained and substituted into the standard curve y = 994.51x + 14285.37 of Example 5 to obtain the Log value of the concentration of Sim in the first reaction solution, and the content of Sim in the water sample to be tested was further calculated.

[0099] (2) Mix 1 mL of the water sample to be tested with 1 mL of 5×10 -4M standard Mal solution was mixed, and then mixed with 100 μL 0.1 mol / L PBS solution to obtain a second reaction solution. Then, the electrochemical SERS dual-mode sensor based on the wearable flexible glove was connected to a handheld micro constant voltage potentiostat, and the sensing finger was immersed in the reaction solution for enrichment treatment, with the enrichment potential controlled at +0.2 V and the enrichment time being 30 s. After the enrichment treatment, the sensing finger was removed from the reaction solution, and the Raman signal of Mal was detected using a handheld Raman spectrometer with an excitation wavelength of 785 nm, a laser power of 80 mW, and an excitation time of 10 s. The Raman intensity of Mal in the first reaction solution was obtained and substituted into the standard curve y = 994.51x + 14285.37 of Example 5 to obtain the Log value of the concentration of Mal in the first reaction solution, and the content of Mal in the water sample to be tested was further calculated.

[0100] Sim and Mal in the water samples were simultaneously detected using high-performance liquid chromatography (HPLC), and the specific detection results are compared with those of this example. The specific detection results are shown in Table 1. As can be seen from Table 1, the electrochemical-SERS analysis results of this example closely match those of the HPLC method, indicating that this method has good detection accuracy and is expected to be further applied to the rapid analysis and detection of pesticide molecules.

[0101] Table 1 Comparison of the detection results of the detection method of the present invention and high performance liquid chromatography

[0102]

[0103] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the explanations of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing an electrochemical SERS dual-mode sensor based on a wearable flexible glove, characterized in that: The following steps are involved: (1) Design a flat finger mold using SolidWorks 3D CAD and print it using a Mojo 3D printer to obtain a finger mold; (2) Design a 125 μm thick stainless steel template using AutoCAD and laser cutting, and set the sensor pattern; (3) The 3D-printed finger mold was inserted into a purple nitrile glove, and the reference electrode, counter electrode, and working electrode were printed on the index finger of the finger mold in sequence according to the sensor pattern prepared in step (2) using a semi-automatic screen printer. After each printing, the electrodes were cured at 85°C for 20 minutes to obtain an electrochemical SERS dual-mode sensor based on a wearable flexible glove. In step (3), the reference electrode is Ag / AgCl ink; the counter electrode and the working electrode are both AuNPs / GO / PDMS flexible electrodes; The AuNPs / GO / PDMS flexible material was prepared by the following method: (S1) preparing a 0.1 mg / mL aqueous solution of graphene oxide, adjusting the pH to 9-10, adding 2 mg / mL of vitamin C, and reacting at 95°C for 15 minutes; then adjusting the concentration of the vitamin C-reduced graphene solution to 10 μm / mL, vacuum filtering, and drying to obtain a graphene membrane; (S2) transferring the graphene film prepared in step (S1) onto the flexible polymer PDMS to obtain a graphene-PDMS hybrid composite film; (S3) 100 mL of H2O and 1 mL of 0.01% HAuCl4 solution were heated to boiling, and then 2.5 mL of 1% trisodium citrate was added. The solution was kept boiling for 10 minutes and then cooled to room temperature to obtain an AuNPs solution. Gold nanoparticles were deposited on the surface of the graphene-PDMS hybrid composite film prepared in step (S2) using an electrochemical workstation at a potential of +0.2 V. Finally, the solution was left to dry at room temperature for one day to obtain an AuNPs / GO / PDMS flexible material.

2. An electrochemical SERS dual-mode sensor based on a wearable flexible glove prepared by the method of claim 1.

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