Electrochemical preparation method of gold nano planar electrode

Abstract

Aiming at the problems of small specific surface area, poor practical application performance and the like of the current commercial gold electrode, the invention provides a simple and efficient method for preparing a gold nano planar electrode based on a glassy carbon electrode, and the method can realize rapid preparation of the gold nano planar electrode by virtue of an electrochemical deposition technology. According to the characterization of low-power and high-power scanning electron microscopes of the prepared gold nano planar electrode, the surface of the electrode is flat, and gold nano particles with uniform sizes are distributed on the surface of the electrode, so that the reliability of the method is shown.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical electrode modification and relates to an electrochemical preparation method of a gold nanometer plane electrode. Background Art

[0002] The development of chemically modified electrodes began in 1975. Its emergence broke through the traditional electrochemical field, which was limited to the study of bare electrode / electrolyte interface, and pioneered the research direction of artificially controlling the electrode surface structure from the chemical state. By modifying the electrode surface with atoms / molecules, customized electrode functions can be achieved, such as catalysis, photoelectricity, electrochromism, surface coordination, enrichment and separation, switching and rectification, stereo organic synthesis, molecular recognition, doping and release, etc., thereby promoting the application of electrochemical electrodes in other fields. It not only promoted the development of the theory of electrode process kinetics, but also showed that it provided a new research direction for the development of the chemical field.

[0003] Gold electrodes have a wide range of uses in biological applications, mainly due to their excellent conductivity, chemical stability and biocompatibility. In particular, in the field of biosensors, gold electrodes are ideal for building highly sensitive electrochemical biosensors. Thanks to the stable Au-S bond, gold electrodes can serve as an effective platform for the immobilization of biomolecules and promote electron transfer between the electrode surface and the immobilized molecules, thereby achieving the output and detection of strong bioelectric signals. Summary of the invention

[0004] In view of the problems of small specific surface area and poor practical application performance of current commercial gold electrodes, the present invention proposes a simple and efficient method for preparing gold nano-planar electrodes based on glassy carbon electrodes based on electrochemical deposition, comprising: Step 1, physically polishing and electrochemically cleaning the glassy carbon electrode in sequence; Step 2: preparing a chloroauric acid solution with a certain concentration as an electrolyte, and adjusting the pH of the electrolyte with dilute hydrochloric acid; Step three, use the glassy carbon electrode cleaned in step one as the working electrode to form a three-electrode system with the reference electrode and the counter electrode, and perform chronoamperometry in the electrolyte prepared in step two to prepare a gold nano-plane electrode.

[0005] Furthermore, the physical polishing in step 1 uses aluminum oxide powder with diameters of 0.3 and 0.05 microns as a polishing agent; The chemical cleaning in step 1 is carried out in a mixed solution of 0.5 M potassium hydroxide, 0.5 M sulfuric acid, 0.1 M sulfuric acid and 0.01 M potassium chloride in sequence using cyclic voltammetry; Further, the concentration of the chloroauric acid solution in step 2 is 3-6 mM, the pH of the electrolyte is 5-6, and the concentration of the dilute hydrochloric acid is 0.1 M; The reference electrode in step 3 is one of Ag / AgCl, Hg / HgO, or a saturated calomel electrode; the counter electrode is one of a platinum wire, a platinum sheet, or a graphite rod electrode; Furthermore, the chronoamperometry operation potential is 0.8-1.2 V vs. RHE, and the operation time is 200-400 seconds.

[0006] The present invention proposes a simple and efficient method for preparing a gold nano-plane electrode based on a glassy carbon electrode. The method can realize the rapid preparation of the gold nano-plane electrode by means of electrochemical deposition technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 and Figure 2 These are low-magnification and high-magnification scanning electron microscope characterization images of the gold nano-plane electrode prepared in Example 1 of the present invention; Example

[0008] An electrochemical preparation method of a gold nano-planar electrode comprises the following steps: 1) The glassy carbon electrode was first physically polished using alumina powder with diameters of 0.3 and 0.05 μm, and then electrochemically cleaned in a mixed solution of 0.5 M potassium hydroxide, 0.5 M sulfuric acid, 0.1 M sulfuric acid, and 0.01 M potassium chloride using cyclic voltammetry; 2) Prepare a 5 mM chloroauric acid solution as the electrolyte, and adjust the pH of the electrolyte to 5.0 using 0.1 M dilute hydrochloric acid; 3) The glassy carbon electrode cleaned in step 1 is used as the working electrode to form a three-electrode system with the Ag / AgCl electrode and the platinum wire counter electrode, and the chronoamperometry is performed in the electrolyte prepared in step 2 with an operating potential of 1.0 V vs. RHE and an operating time of 300 seconds to prepare a gold nano-plane electrode. Example

[0009] An electrochemical preparation method of a gold nano-planar electrode comprises the following steps: 1) The glassy carbon electrode was first physically polished using alumina powder with diameters of 0.3 and 0.05 μm, and then electrochemically cleaned in a mixed solution of 0.5 M potassium hydroxide, 0.5 M sulfuric acid, 0.1 M sulfuric acid, and 0.01 M potassium chloride using cyclic voltammetry; 2) Prepare a 3 mM chloroauric acid solution as the electrolyte, and adjust the pH of the electrolyte to 6.0 using 0.1 M dilute hydrochloric acid; 3) The glassy carbon electrode cleaned in step 1 is used as the working electrode to form a three-electrode system with the Hg / HgO electrode and the platinum counter electrode, and the chronoamperometry is performed in the electrolyte prepared in step 2 with an operating potential of 1.2 V vs. RHE and an operating time of 400 seconds to prepare a gold nano-plane electrode. Example

[0010] An electrochemical preparation method of a gold nano-planar electrode comprises the following steps: 1) The glassy carbon electrode was first physically polished using alumina powder with diameters of 0.3 and 0.05 μm, and then electrochemically cleaned in a mixed solution of 0.5 M potassium hydroxide, 0.5 M sulfuric acid, 0.1 M sulfuric acid, and 0.01 M potassium chloride using cyclic voltammetry; 2) Prepare a 6 mM chloroauric acid solution as the electrolyte, and adjust the pH of the electrolyte to 5.5 using 0.1 M dilute hydrochloric acid; 3) The glassy carbon electrode cleaned in step 1 is used as the working electrode to form a three-electrode system with a saturated calomel electrode and a graphite rod electrode as a counter electrode, and the chronoamperometry is performed in the electrolyte prepared in step 2 with an operating potential of 0.9 V vs. RHE and an operating time of 200 seconds to prepare a gold nanoplane electrode.

[0011] Figure 1 and Figure 2 These are low-magnification and high-magnification scanning electron microscope characterization images of the gold nano-planar electrode prepared in Example 1 of the present invention. It can be seen that the electrode surface is flat and has uniformly sized gold nanoparticles distributed on it, which illustrates the reliability of this method.

[0012] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A simple and efficient method for preparing a gold nano-planar electrode based on a glassy carbon electrode, comprising: Step 1, physically polishing and electrochemically cleaning the glassy carbon electrode in sequence; Step 2: preparing a chloroauric acid solution with a certain concentration as an electrolyte, and adjusting the pH of the electrolyte with dilute hydrochloric acid; Step three, use the glassy carbon electrode cleaned in step one as the working electrode to form a three-electrode system with the reference electrode and the counter electrode, and perform chronoamperometry in the electrolyte prepared in step two to prepare a gold nano-plane electrode.

2. The method for preparing a gold nano-plane electrode based on a glassy carbon electrode according to claim 1, characterized in that: The physical polishing in step 1 uses aluminum oxide powder with diameters of 0.3 and 0.05 microns as a polishing agent; The chemical cleaning in step 1 is performed in a mixed solution of 0.5 M potassium hydroxide, 0.5 M sulfuric acid, 0.1 M sulfuric acid and 0.01 M potassium chloride in sequence using cyclic voltammetry.

3. The method for preparing a gold nano-plane electrode based on a glassy carbon electrode according to claim 1, characterized in that: The concentration of the chloroauric acid solution in step 2 is 3-6 mM, the pH of the electrolyte is 5-6, and the concentration of the dilute hydrochloric acid is 0.1 M.

4. The method for preparing a gold nano-plane electrode based on a glassy carbon electrode according to claim 1, characterized in that: The reference electrode in step 3 is one of Ag / AgCl, Hg / HgO, or a saturated calomel electrode; the counter electrode is one of a platinum wire, a platinum sheet, or a graphite rod electrode; Furthermore, the chronoamperometry operation potential is 0.8-1.2 V vs. RHE, and the operation time is 200-400 seconds.

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