A nano liquid metal modified electrode and a preparation method and application thereof

Abstract

The application discloses a kind of nano liquid metal modified electrode and its preparation method and application, the preparation method includes the following steps: S1: liquid metal, elemental iron nanoparticles, polyphenol solution is added to solvent one, ultrasonic treatment is carried out using ultrasonic cell disrupter, and elemental iron liquid metal nanoparticles are formed, and suspension one is obtained;S2: the pH of suspension one is adjusted, and metal-polyphenol supramolecule is self-assembled on the surface of elemental iron liquid metal nanoparticles to generate, and metal-polyphenol supramolecule modified iron-containing liquid metal nanomaterial is obtained;S3: the material obtained in step S2 is washed, dispersed, and suspension two is obtained;S4: naphthol solution and solvent two are added to suspension two, and after being uniformly dispersed, it is coated on the surface of support electrode, and nano liquid metal modified electrode is obtained.The nano liquid metal modified electrode prepared by the application can detect imidacloprid in ultra-trace amount, and has the characteristics of high sensitivity, strong anti-interference and low detection limit.

Description

Technical Field

[0001] This invention relates to the field of electrochemical analysis and detection technology, and in particular to a nano-liquid metal modified electrode, its preparation method, and its application. Background Technology

[0002] Imidacloprid is a commonly used neonicotinoid insecticide, widely used in the cultivation of wheat, corn, cotton, vegetables, tea, and fruit trees, resulting in high levels of imidacloprid residues in agricultural products and the soil and water environment of production areas. Even trace amounts of imidacloprid residues can exacerbate liver failure in the elderly, cause poisoning in pregnant women, and lead to fetal malformations, seriously endangering human life and health. Therefore, establishing a highly sensitive, selective, rapid, and convenient method for detecting imidacloprid is of great significance for food safety and environmental protection.

[0003] Currently, the detection of imidacloprid mainly employs liquid chromatography and electrochemical detection methods. Among these, electrochemical detection offers advantages such as simplicity, rapid response, and low cost, giving it a unique edge in pesticide residue detection. However, current electrochemical detection methods are insufficient for ultra-trace imidacloprid detection, necessitating the development of higher-performance working electrodes to improve detection sensitivity. Summary of the Invention

[0004] To address the above-mentioned problems, the present invention aims to provide a nano-liquid metal modified electrode, its preparation method, and its application.

[0005] The technical solution of the present invention is as follows:

[0006] On the one hand, a method for preparing a nano-liquid metal-modified electrode is provided, comprising the following steps:

[0007] Liquid metal, elemental iron nanoparticles, and polyphenol solution were added to solvent one, and ultrasonic treatment was performed using an ultrasonic cell disruptor to form liquid metal nanoparticles containing elemental iron, thus obtaining suspension one.

[0008] Naphthol solution and solvent 2 are added to the suspension and dispersed evenly before being coated onto the surface of the supporting electrode to obtain a nano-liquid metal modified electrode.

[0009] Preferably, the liquid metal is gallium or a gallium alloy, and the gallium alloy is a gallium-indium alloy, a gallium-tin alloy, or a gallium-indium-tin alloy.

[0010] Preferably, the weight ratio of the liquid metal to the elemental iron nanoparticles is 10:0.5 to 5.

[0011] Preferably, the polyphenol solution is any one of tannic acid solution, gallic acid solution, catechin solution, and anthocyanin solution.

[0012] Preferably, the mass concentration of the polyphenol solution is 5–200 mg / mL.

[0013] As a preferred method, when using an ultrasonic cell disruptor for ultrasonic treatment, ultrasonic treatment should be performed for 20 to 90 minutes at a power of 450–1200W.

[0014] Preferably, the following steps are included before adding the naphthol solution and solvent II:

[0015] The pH of the first suspension is adjusted to allow the surface of the liquid metal nanoparticles containing elemental iron to self-assemble into metal-polyphenol supramolecular structures, thereby obtaining iron-containing liquid metal nanomaterials modified with metal-polyphenol supramolecular structures.

[0016] The iron-containing liquid metal nanomaterial modified with metal-polyphenol supramolecular structure is washed and redispersed in solvent two to obtain suspension two.

[0017] The naphthol solution and the solvent II are added to the second suspension.

[0018] Preferably, when adjusting the pH of the first suspension, the pH of the suspension is adjusted to 6.5-8.5.

[0019] On the other hand, a nano-liquid metal modified electrode prepared by any one of the above preparation methods is also provided, and its application in the electrochemical detection of imidacloprid is also provided.

[0020] The beneficial effects of this invention are:

[0021] The nano-liquid metal modified electrode prepared by this invention can perform ultra-trace detection of imidacloprid, and has the characteristics of high sensitivity, strong anti-interference, and low detection limit. It can successfully perform imidacloprid residue analysis and detection on actual samples of fruits and vegetables such as tomatoes, cucumbers, bananas, radishes, and sweet potatoes. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 EGa in Example 1 0.75 In 0.25 Scanning electron microscope images;

[0024] Figure 2 EGa in Example 1 0.66 In0.22 Fe 0.12 Scanning electron microscope image from @MPN;

[0025] Figure 3 This is a schematic diagram illustrating the results of using the electrode prepared in Example 1 for electrochemical imidacloprid detection; wherein, Figure 3 (a) is a schematic diagram of the differential pulse voltammetry results for different concentrations of imidacloprid. Figure 3 (b) is a schematic diagram showing the relationship between peak current and imidacloprid concentration.

[0026] Figure 4 This is a schematic diagram of the linear sweep voltammetric curves of the electrodes prepared in Examples 1-3 with 10 nmol / L imidacloprid.

[0027] Figure 5 A schematic diagram showing the current response of the electrode prepared in Example 1 to imidacloprid under different interference conditions. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and technical features described in this application can be combined with each other. It should also be pointed out that, unless otherwise indicated, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terms "comprising" or "including" and similar words used in this invention refer to elements or objects preceding the word that encompass the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0029] On one hand, the present invention provides a method for preparing a nano-liquid metal-modified electrode, comprising the following steps:

[0030] S1: Liquid metal, elemental iron nanoparticles, and polyphenol solution are added to solvent one, and ultrasonic treatment is performed using an ultrasonic cell disruptor to form liquid metal nanoparticles containing elemental iron, thus obtaining suspension one.

[0031] In one specific embodiment, the liquid metal is gallium or a gallium alloy, and the gallium alloy is a gallium-indium alloy, a gallium-tin alloy, or a gallium-indium-tin alloy. Optionally, the mass ratio of gallium, indium, and tin in the liquid metal is (65-80%):(0-30%):(0-20%).

[0032] It should be noted that the liquid metal in the above embodiments is only a preferred liquid metal of the present invention. The present invention mainly utilizes the room-temperature liquid state characteristics of liquid metal in combination with other technical features to enable the nano-liquid metal modified electrode of the present invention to perform ultra-trace detection of imidacloprid. Other liquid metals in the prior art can also be applied to the present invention, such as mercury, but it is highly toxic, therefore, it is rarely chosen as the liquid metal of the present invention in practical applications. In addition, gallium can also be liquid when other metals are added.

[0033] In one specific embodiment, the weight ratio of the liquid metal to the elemental iron nanoparticles is 10:0.5 to 5; optionally, the particle size of the elemental iron nanoparticles is 2 to 800 nm; further, the particle size of the elemental iron nanoparticles is 2 to 100 nm.

[0034] In one specific embodiment, the polyphenol solution is any one of tannic acid solution, gallic acid solution, catechin solution, and anthocyanin solution. Optionally, the mass concentration of the polyphenol solution is 5–200 mg / mL.

[0035] It should be noted that the polyphenol solution in the above embodiments is only a preferred polyphenol solution of the present invention, and other polyphenols in the prior art can also be applied to the present invention.

[0036] In one specific embodiment, when using an ultrasonic cell disruptor for ultrasonic treatment, the ultrasonic treatment is performed for 20 to 90 minutes at a power of 450 to 1200 W.

[0037] It should be noted that the present invention uses an ultrasonic cell disruptor for ultrasonic treatment. The power and processing time used in the above embodiments are only preferred parameters for this embodiment. Any relevant methods and processing parameters that can break the liquid metal into uniform nano-liquid metal can be applied to the present invention.

[0038] S2: Add naphthol solution and solvent two to the suspension one, disperse them evenly, and then coat them on the surface of the supporting electrode to obtain a nano-liquid metal modified electrode.

[0039] In one specific embodiment, the first solvent is selected from deionized water, ethanol, and 10% boric acid, the second solvent is selected from deionized water or ethanol, and the supporting electrode is carbon cloth, carbon paper, or glassy carbon electrode; optionally, the carbon paper is hydrophilic carbon paper.

[0040] In one specific embodiment, the following steps are included before adding the naphthol solution and solvent II:

[0041] S21: Adjust the pH of the suspension to allow the surface of the liquid metal nanoparticles containing elemental iron to self-assemble into metal-polyphenol supramolecular structures, thereby obtaining iron-containing liquid metal nanomaterials modified with metal-polyphenol supramolecular structures.

[0042] In one specific embodiment, when adjusting the pH of the first suspension, the pH of the first suspension is adjusted to 6.5-8.5. Optionally, the pH is adjusted using a pH buffer solution; optionally, the pH buffer solution is a 3-(N-morpholino)propanesulfonic acid buffer solution or a phosphate buffer solution.

[0043] It should be noted that the pH buffer solution used in the above embodiments is only a preferred pH buffer solution of the present invention. Its main function is to adjust the pH of the suspension one, allowing the elemental iron nanoparticles and the polyphenol solution to form a metal-polyphenol supramolecular structure, which then modifies the liquid metal, thereby obtaining iron-containing liquid metal nanomaterials modified with the metal-polyphenol supramolecular structure. Any related method that can adjust the pH of the suspension one to 6.5-8.5 to achieve the above objective is applicable to the present invention.

[0044] S22: The iron-containing liquid metal nanomaterial modified with metal-polyphenol supramolecular structure is washed and redispersed in solvent two to obtain suspension two; the naphthol solution and solvent two are added to suspension two.

[0045] In one specific embodiment, the iron-containing liquid metal nanomaterial modified with metal-polyphenol supramolecular technology was washed alternately several times with ethanol and deionized water.

[0046] On the other hand, a nano-liquid metal modified electrode prepared by any one of the above preparation methods is also provided, and its application in the electrochemical detection of imidacloprid is also provided.

[0047] Example 1

[0048] A nano-liquid metal-modified electrode is prepared by the following steps:

[0049] (1) Weigh 0.33 g of gallium and 0.11 g of indium, mix them and put them into a 25 mL beaker. Heat in a water bath at 80 °C for 1 h, stirring with a glass rod during the process. After cooling to room temperature, a liquid metal containing 75 wt% Ga and 25 wt% In is obtained, denoted as EGa. 0.75 In 0.25 . Figure 1 For EGa 0.75 In 0.25 Scanning electron microscope image.

[0050] (2) Weigh 0.06g of elemental iron nanoparticles with an average diameter of 50nm and pour them into step (1) containing EGa 0.75In 0.25 Add 15 mL of a 40 mg / mL tannic acid aqueous solution to a beaker. Place the beaker in an ice-water bath and sonicate at 800 W for 10 min using a cell disruptor, then sonicate at 500 W for 30 min to obtain a suspension.

[0051] (3) Pour the suspension obtained in step (2) into a 50 mL centrifuge tube, add 15 mL of 0.05 mol / L 3-(N-morpholino)propanesulfonic acid buffer solution (pH = 8.0), vortex for 30 s, wash three times alternately with ethanol and deionized water, centrifuge at 6000 r / min for 3 min, remove the supernatant, and redisperse the remaining nanoparticles in 30 mL of ethanol to obtain a dispersion and label it EGa. 0.66 In 0.22 Fe 0.12 @MPN. Figure 2 For EGa 0.66 In 0.22 Fe 0.12 Scanning electron microscope image from @MPN.

[0052] (4) The EGa prepared in step (3) 0.66 In 0.22 Fe 0.12 @Vortex the MPN dispersion for 30 seconds to ensure uniform dispersion. Transfer 250 μL to a 2 mL centrifuge tube, add 730 μL of deionized water and 20 μL of naphthol solution, shake well, and then sonicate for 10 min.

[0053] (5) Take 10 μL of the dispersion obtained in step (4) and drop it onto the clean glassy carbon electrode surface. After air drying, the nano-liquid metal modified electrode is obtained, denoted as EGa. 0.66 In 0.22 Fe 0.12 @MPN modified glassy carbon electrode.

[0054] Example 2

[0055] Unlike Example 1, the liquid metal used in this example was prepared through the following steps: 0.3g of gallium, 0.1g of indium, and 0.04g of tin were weighed, mixed, and placed in a 25mL beaker. The mixture was heated in an 80°C water bath for 1 hour with stirring using a glass rod. After cooling to room temperature, a liquid metal containing 68wt% Ga, 22wt% In, and 10wt% Sn was obtained, denoted as EGa. 0.68 In 0.22 Sn 0.10 The nano-liquid metal-modified electrode obtained in this embodiment is denoted as EGa. 0.6 In 0.2 Sn 0.08 Fe 0.12@MPN modified glassy carbon electrode.

[0056] Example 3

[0057] Unlike Example 1, step (3) is omitted in this example, i.e., the pH of the suspension obtained in step (2) is not adjusted to generate MPN. The nano-liquid metal modified electrode obtained in this example is denoted as EGa. 0.66 In 0.22 Fe 0.12 Modified glassy carbon electrode.

[0058] Example 4

[0059] Unlike Example 1, the polyphenol solution used in this example is an aqueous solution of gallic acid. The nano-liquid metal-modified electrode obtained in this example is denoted as EGa. 0.66 In 0.22 Fe 0.12 @g-MPN modified glassy carbon electrode.

[0060] Example 5

[0061] Unlike Example 1, the polyphenol solution used in this example is an aqueous solution of catechins. The nano-liquid metal modified electrode obtained in this example is denoted as EGa. 0.66 In 0.22 Fe 0.12 @c-MPN modified glassy carbon electrode.

[0062] Example 6

[0063] Unlike Example 1, the polyphenol solution used in this example is an anthocyanin aqueous solution. The nano-liquid metal modified electrode obtained in this example is denoted as EGa. 0.66 In 0.22 Fe 0.12 @a-MPN modified glassy carbon electrode.

[0064] Example 7

[0065] Unlike Example 1, the elemental iron nanoparticles used in this example are elemental iron nanoparticles with an average diameter of 20 nm. The nano-liquid metal modified electrode obtained in this example is denoted as EGa. 0.66 In 0.22 20-Fe 0.12 @MPN modified glassy carbon electrode.

[0066] Example 8

[0067] Unlike Example 1, the elemental iron nanoparticles used in this example have an average diameter of 100 nm. The nano-liquid metal modified electrode obtained in this example is denoted as EGa.0.66 In 0.22 100-Fe 0.12 @MPN modified glassy carbon electrode.

[0068] Comparative Example 1

[0069] Unlike Example 1, this comparative example replaces elemental iron nanoparticles with elemental titanium nanoparticles of the same size. The modified electrode obtained in this comparative example is denoted as EGa. 0.66 In 0.22 Ti 0.12 @MPN modified glassy carbon electrode.

[0070] Comparative Example 2

[0071] Unlike Example 1, this comparative example replaces elemental iron nanoparticles with elemental copper nanoparticles of the same size. The modified electrode obtained in this comparative example is denoted as EGa. 0.66 In 0.22 Cu 0.12 @MPN modified glassy carbon electrode.

[0072] Test Example 1

[0073] The modified electrodes of each embodiment and comparative example were used for electrochemical imidacloprid detection: 0.1 mol / L disodium hydrogen phosphate / citric acid electrolyte (pH = 3.0) containing different concentrations (1 pmol / L, 5 pmol / L, 10 pmol / L, 50 pmol / L, 100 pmol / L, 500 pmol / L, 1 nmol / L, 5 nmol / L, 10 nmol / L, 50 nmol / L, 100 nmol / L, 1 μmol / L) of imidacloprid was bubbled with high-purity nitrogen for 30 min to remove oxygen. The modified electrode was used as the working electrode, a platinum wire electrode as the counter electrode, and a saturated silver chloride electrode as the reference electrode. Differential pulse voltammetry curves were measured for this series of solutions. The potential range was set to 0.3–0.75 V, the amplitude to 50 mV, the pulse width to 0.2 s, and the pulse period to 0.5 s.

[0074] The test results of Example 1 are as follows: Figure 3 As shown, from Figure 3 It can be seen that EGa 0.66 In 0.22 Fe 0.12 The @MPN-modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -86.39log(C) + 187.39(R) 2When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.3 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0075] EGa in Example 2 0.6 In 0.2 Sn 0.08 Fe 0.12 The @MPN-modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -90.31log(C) + 187.05(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.4 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0076] EGa in Example 3 0.66 In 0.22 Fe 0.12 The modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -98.15log(C) + 186.33(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.7 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0077] EGa in Example 4 0.66 In 0.22 Fe 0.12 @g-MPN modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -86.36log(C) + 187.41(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.3 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0078] EGa in Example 5 0.66 In 0.22 Fe 0.12 The @c-MPN modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -86.38log(C) + 187.37(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.3 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0079] EGa in Example 60.66 In 0.22 Fe 0.12 The @a-MPN-modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -86.40log(C) + 187.29(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.3 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0080] EGa in Example 7 0.66 In 0.22 20-Fe 0.12 The @MPN-modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -86.40log(C) + 185.44(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.3 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0081] EGa in Example 8 0.66 In 0.22 100-Fe 0.12 The @MPN-modified glassy carbon electrode exhibits good current response to imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L. The relationship between the peak current I and the imidacloprid concentration C is: I = -86.38log(C) + 184.32(R) 2 When the signal-to-noise ratio (S / N) is 3, the detection limit is 0.3 pmol / L, achieving ultra-trace detection of the pesticide imidacloprid.

[0082] Comparative Example 1 EGa 0.66 In 0.22 Ti 0.12 The @MPN-modified glassy carbon electrode showed no peak current for imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L, and therefore could not be used for the electrochemical detection of imidacloprid.

[0083] Comparative Example 2 EGa 0.66 In 0.22 Cu 0.12 The @MPN-modified glassy carbon electrode showed no peak current for imidacloprid concentrations ranging from 1 pmol / L to 1 μmol / L, and therefore could not be used for the electrochemical detection of imidacloprid.

[0084] Test Example 2

[0085] Cyclic voltammetry was used to detect imidacloprid using the modified electrodes prepared in Examples 1, 2, and 3, respectively. The imidacloprid concentration was 10 nmol / L, the electrolyte was 0.1 mol / L disodium hydrogen phosphate / citric acid buffer (pH = 3.0), and the scan rate was 100 mV / s. The results are as follows: Figure 4 As shown.

[0086] from Figure 4 It can be seen that the nano-liquid metal modified electrodes of the present invention can successfully detect imidacloprid and effectively amplify the oxidation current of imidacloprid, thereby enhancing the detection sensitivity.

[0087] Test Example 3

[0088] The specificity of the modified electrodes prepared in each embodiment for imidacloprid detection was investigated: the effects of some common inorganic ions and neonicotinoid pesticides on the current signal for imidacloprid detection were examined. (The experiment was conducted in the presence of 100 nmol / L K...) + Mg 2+ Ca 2+ Cl – PO4 3– When thiamethoxam, chlorpyrifos, and thiamethoxam were added, the current response of 1 nmol / L imidacloprid was detected using differential pulse voltammetry. The changes in peak current (I0 and I, respectively) before and after the addition of these interfering substances were recorded. The test results of Example 1 are as follows: Figure 5 As shown.

[0089] from Figure 5 It can be seen that when detecting 1 nmol / L imidacloprid, the response current generated by adding 100 times the concentration of these common inorganic ions or neonicotinoid pesticides showed no significant change compared to the absence of these interfering substances (relative standard deviation ≤ ±5.0%). This indicates that the nano-liquid metal modified electrode prepared in Example 1 has good specificity for imidacloprid detection.

[0090] The test results of other embodiments and the conclusions drawn from these test results are similar to those of Embodiment 1, and are omitted here.

[0091] Test Example 4

[0092] The modified electrodes prepared in each embodiment were used for actual sample detection to examine their accuracy. Crushed bananas and sweet potatoes were used as samples, diluted with 0.1 mol / L disodium hydrogen phosphate / citric acid buffer solution (pH = 3.0), and different concentrations of imidacloprid were added. The concentration of imidacloprid was then detected using the modified electrodes prepared in each embodiment. The test results for Example 1 are shown in Table 1.

[0093] Table 1. Imidacloprid detection in actual samples

[0094]

[0095] As can be seen from Table 1, the recovery rate of the nano-liquid metal modified electrode in Example 1 was 99.33% to 107.33%, and the relative standard deviation was 1.52% to 4.76%, indicating that the nano-liquid metal modified electrode prepared in this invention is feasible for the detection and analysis of imidacloprid in actual samples.

[0096] The test results of other embodiments and the conclusions drawn from these test results are similar to those of Embodiment 1, and are omitted here.

[0097] In summary, this invention not only successfully detects imidacloprid but also enables ultra-trace detection of imidacloprid, featuring high sensitivity, strong anti-interference ability, and low detection limit. It can be successfully applied to the residue analysis of imidacloprid in fruits and vegetables. Compared with existing technologies, this invention represents a significant advancement.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a nano-liquid metal-modified electrode, characterized in that, Includes the following steps: Liquid metal, elemental iron nanoparticles, and polyphenol solution were added to solvent one, and ultrasonic treatment was performed using an ultrasonic cell disruptor to form liquid metal nanoparticles containing elemental iron, thus obtaining suspension one. Naphthol solution and solvent 2 are added to the suspension and dispersed evenly before being coated onto the surface of the supporting electrode to obtain a nano-liquid metal modified electrode.

2. The method for preparing the nano-liquid metal-modified electrode according to claim 1, characterized in that, The liquid metal is gallium or a gallium alloy, and the gallium alloy is a gallium-indium alloy, a gallium-tin alloy, or a gallium-indium-tin alloy.

3. The method for preparing the nano-liquid metal-modified electrode according to claim 1, characterized in that, The weight ratio of the liquid metal to the elemental iron nanoparticles is 10:0.5 to 5.

4. The method for preparing the nano-liquid metal-modified electrode according to claim 1, characterized in that, The polyphenol solution is any one of tannic acid solution, gallic acid solution, catechin solution, and anthocyanin solution.

5. The method for preparing the nano-liquid metal-modified electrode according to claim 4, characterized in that, The mass concentration of the polyphenol solution is 5–200 mg / mL.

6. The method for preparing a nano-liquid metal-modified electrode according to claim 1, characterized in that, When using an ultrasonic cell disruptor for ultrasonic treatment, ultrasonic treatment should be performed for 20 to 90 minutes at a power of 450–1200W.

7. The method for preparing a nano-liquid metal-modified electrode according to any one of claims 1-6, characterized in that, Before adding the naphthol solution and solvent II, the following steps are also included: The pH of the first suspension is adjusted to allow the surface of the liquid metal nanoparticles containing elemental iron to self-assemble into metal-polyphenol supramolecular structures, thereby obtaining iron-containing liquid metal nanomaterials modified with metal-polyphenol supramolecular structures. The iron-containing liquid metal nanomaterial modified with metal-polyphenol supramolecular structure is washed and redispersed in solvent two to obtain suspension two. The naphthol solution and the solvent II are added to the second suspension.

8. The method for preparing a nano-liquid metal-modified electrode according to claim 7, characterized in that, When adjusting the pH of the first suspension, the pH of the suspension is adjusted to 6.5-8.

5.

9. A nano-liquid metal-modified electrode, characterized in that, It is prepared by the method of any one of claims 1-8 for preparing nano-liquid metal modified electrodes.

10. The application of the nano-liquid metal modified electrode as described in claim 9 in the electrochemical detection of imidacloprid.

Images