Neural electrode preparation method based on composite electrochemical technology

Abstract

The invention provides a neural electrode and a preparation method thereof.The preparation method of the neural electrode comprises the steps that a metal nano-material aqueous solution serves as electrodeposition liquid, electrochemical deposition is conducted on a recording site of a pretreated metal electrode through chronopotentiometry and cyclic voltammetry in sequence, so that the surface of the recording site is modified with a metal nano-material, and the metal nano-material is obtained; the metal nanometer material is selected from one or more of manganese, gold, silver, copper and iron.

Description

Technical Field

[0001] The present disclosure relates to the technical field of neural electrodes, and in particular to a neural electrode and a preparation method thereof. Background Art

[0002] As a bridge between the nervous system and external devices, neural electrodes play an important role in capturing and regulating neural activities. With the continuous advancement of science and technology, the demand for high-performance neural electrodes that can perform long-term, high-resolution monitoring and regulation of neural activities is growing.

[0003] However, the inherent properties of electrode materials, such as excellent chemical stability and mechanical strength, provide the necessary durability for the electrodes, but also limit the feasibility of modifying the electrode surface, which to some extent restricts the expansion and optimization of neural electrode performance. At present, there is still a lack of neural electrode preparation methods that can overcome the limitations of existing technologies and improve the overall performance of electrodes. Summary of the invention

[0004] In view of this, the main purpose of the present disclosure is to provide a neural electrode and a preparation method thereof, in order to at least partially solve at least one of the above-mentioned technical problems.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] In one aspect of the present disclosure, a method for preparing a neural electrode is provided, comprising:

[0007] Using an aqueous solution of metal nanomaterials as an electrodeposition solution, electrochemical deposition is performed on the recording site of the pretreated metal electrode using chronopotentiometry and cyclic voltammetry in sequence to modify the metal nanomaterials on the surface of the recording site to obtain a neural electrode deposited with metal nanomaterials, wherein the metal nanomaterials are selected from one or more of manganese, gold, silver, copper, and iron.

[0008] As another aspect of the present disclosure, a neural electrode prepared by the above preparation method is provided, wherein the neural electrode comprises an electrode, and a surface of a recording site of the electrode is modified with a metal nanomaterial.

[0009] According to the embodiments of the present disclosure, a metal nanomaterial aqueous solution with good biocompatibility is used as an electrodeposition solution, and a constant current method is first used for preliminary deposition to firmly attach the metal nanomaterial to the electrode surface, effectively reducing the electrochemical impedance of the neural electrode, and then further deposition is performed by cyclic voltammetry to improve the charge storage capacity of the neural electrode. A neural electrode with high-sensitivity signal acquisition, stable stimulation output and good biocompatibility is prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1is a schematic diagram of preparing a neural electrode in an embodiment of the present disclosure;

[0011] Figure 2 is a surface morphology diagram of the neural electrode in Example 4 of the present disclosure;

[0012] Figure 3 is a graph of the photoelectron energy spectrum of the surface of the neural electrode in Example 4 of the present disclosure;

[0013] Figure 4 It is a test diagram of the electrical performance of the neural electrodes in Example 4 and Comparative Example 1 of the present disclosure;

[0014] Figure 5 It is a test diagram of the electrical performance of the neural electrodes in Example 4, Comparative Example 1, Comparative Example 3, and Comparative Examples 6-7 of the present disclosure. DETAILED DESCRIPTION

[0015] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments.

[0016] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this disclosure.

[0017] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0018] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0019] The performance of neural electrodes has been improved by using various surface modification techniques such as chemical vapor deposition, electroplating, photolithography and plasma etching, but these methods face problems such as insufficient coating adhesion, complicated processes and high costs, making it difficult to meet the needs of large-scale production. In addition, although electrochemical modification technology has the advantages of uniform coating and high cost-effectiveness, its functionalization capabilities are relatively single, making it difficult to construct complex structures on the electrode surface, and the stability and durability of the coating are limited. In addition, due to the differences in the redox ability of different electrolytes on the electrode substrate, there are still challenges in using electrochemical technology to modify the neural electrode substrate and achieve a comprehensive improvement in the performance of a wide range of neural electrodes.

[0020] In the process of realizing the concept of the present disclosure, it was found that in the process of preparing neural electrodes, metal nanomaterials were first uniformly deposited on the surface of neural electrodes by chronopotentiometry deposition, which can effectively reduce the electrochemical impedance of neural electrodes. Subsequently, secondary deposition was performed again using cyclic voltammetry, and the periodic change of the electrode potential was quasi-controlled, which further promoted the uniform coverage of nanomaterials, increased the surface area of ​​the electrode, and formed more charge storage sites on the electrode surface, thereby improving the electrochemical activity and charge storage capacity. Through this composite electrochemical deposition technology, metal nanomaterials with good biocompatibility are effectively modified on the electrode surface, thereby designing a preparation method that can comprehensively improve the performance of the electrode. The prepared neural electrode can not only adapt to the biological environment of long-term implantation, but also achieve efficient, safe and stable recording and regulation of the nervous system, providing strong technical support for clinical applications.

[0021] According to an embodiment of one aspect of the present disclosure, a method for preparing a neural electrode is provided, comprising:

[0022] Using an aqueous solution of metal nanomaterials as an electrodeposition solution, electrochemical deposition is performed on the recording site of the pretreated metal electrode using chronopotentiometry and cyclic voltammetry in sequence to modify the metal nanomaterials on the surface of the recording site to obtain a neural electrode deposited with metal nanomaterials, wherein the metal nanomaterials are selected from one or more of manganese, gold, silver, copper, and iron.

[0023] According to the embodiments of the present disclosure, an aqueous solution of metal nanomaterials with good biocompatibility is used as an electrodeposition solution, and a preliminary deposition is first performed by a constant current method. During the deposition process, the current intensity remains constant, which helps to control the reduction and deposition of metal ions at a stable rate on the electrode surface into nanostructures, promotes the formation of a dense and uniform metal nanomaterial layer, effectively increases the surface area of ​​the electrode, and provides more charge transfer channels, thereby reducing the transmission resistance of electrons between the electrode and the electrolyte interface, and reducing the electrochemical impedance of the neural electrode. Subsequently, the electrode is subjected to secondary deposition by cyclic voltammetry. By controlling the repeated scanning of the electrode potential, the reversible redox reaction of active substances such as metal ions on the electrode surface is promoted, which helps the uniform deposition of metal nanomaterials on the electrode, while forming more charge storage sites on the electrode surface, thereby increasing the charge storage capacity of the neural electrode.

[0024] According to an embodiment of the present disclosure, the method for preparing a neural electrode further includes:

[0025] The area other than the area where the metal nanomaterial is deposited is wrapped with an insulating material. That is, the recording site of the neural electrode is modified by depositing metal nanomaterials, and the area outside the recording site is wrapped with an insulating material. By coating the area outside the recording site with insulating material, the conductive interference of the area outside the recording site is effectively isolated, ensuring that only the recording site part can accurately capture the electrical signal of neural activity, thereby significantly improving the sensitivity and signal-to-noise ratio of the signal, and further improving the accuracy and reliability of signal acquisition. Among them, the insulating material is selected from one of polyimide, polyparaxylene, polytetrafluoroethylene, and polymethyl methacrylate. Selecting an insulating material with a high dielectric constant and good biocompatibility can effectively isolate the electrical signal interference in the non-signal acquisition area and enhance the accuracy and stability of signal acquisition. At the same time, it can reduce the immune response with biological tissues and ensure the safety and effectiveness of long-term implantation of neural electrodes in the body.

[0026] According to an embodiment of the present disclosure, the metal electrode material is selected from one of platinum, platinum-iridium alloy, gold, silver, copper, tungsten, nickel-titanium alloy, and stainless steel. Selecting a metal material with excellent conductivity and good biocompatibility ensures that the neural electrode can efficiently and accurately capture and transmit neural signals while reducing stimulation and damage to biological tissues. The diameter of the metal electrode is 2 μm~200 μm, for example, 2 μm, 10 μm, 50 μm, 100 μm, 200 μm, etc.

[0027] According to the embodiments of the present disclosure, the metal nanomaterial is in the form of one or more of nanoclusters, nanoparticles, single-atom nanomaterials, quantum dots, two-dimensional materials, and organic metal framework materials. The different forms of metal nanomaterials provide a variety of design options for neural electrodes to meet different application requirements. For example, nanoclusters and nanoparticles can significantly improve the electrocatalytic activity and charge transfer rate of electrodes due to their large specific surface area and abundant active sites, thereby enhancing the sensitivity of signal acquisition.

[0028] According to the embodiments of the present disclosure, the concentration of the aqueous solution of the metal nanomaterial is 0.1 to 1 mg / mL, for example, it can be 0.1 mg / mL, 0.3 mg / mL, 0.5 mg / mL, 0.7 mg / mL, 1 mg / mL, etc. When the concentration of the aqueous solution of the metal nanomaterial is too low, the content of the metal nanomaterial in the solution is low, and the deposition process of the material is slow, resulting in reduced preparation efficiency. On the contrary, if the concentration of the metal nanomaterial in the aqueous solution is too high, it is easy to cause the metal nanomaterial to agglomerate during the deposition process, and the clusters formed will have an adverse effect on the adhesion of the deposited layer, resulting in a decrease in adhesion firmness.

[0029] According to an embodiment of the present disclosure, the pretreatment includes: removing the passivation layer on the surface of the metal electrode by sulfuric acid activation, and depositing gold nanoparticles on the surface of the recording site of the metal electrode after sulfuric acid activation.

[0030] Depositing gold nanoparticles on the surface of the recording site of the metal electrode activated by sulfuric acid includes: depositing gold nanoparticles on the recording site of the metal electrode activated by sulfuric acid by electrochemical deposition to obtain the recording site of the pretreated metal electrode.

[0031] Among them, the electrochemical deposition method of depositing gold nanoparticles includes one or more of chronoamperometry, multi-potential step method, and cyclic voltammetry, and the total deposition times are 1 to 5 times, for example, 1 time, 2 times, 3 times, 5 times, etc.

[0032] The parameters of the chronoamperometry deposition are a voltage range of -1 to 2 V, such as -1 V, -0.5 V, 0.5 V, 1 V, 2 V, etc., and a step length of 10 to 100 steps, such as 10 steps, 30 steps, 50 steps, 70 steps, 100 steps, etc.

[0033] The parameters of the multi-potential step deposition method are a deposition interval of 2 to 5 s, for example, 2 s, 2.5 s, 3 s, 4s, 5 s, etc., and a step voltage of 0.05 to 0.1 V, for example, 0.05 V, 0.06 V, 0.08 V, 0.07 V, 0.09 V, 0.1 V, etc.

[0034] The parameters of cyclic voltammetry deposition are that the deposition voltage ranges from -3 to 3 V, for example, -3 V, -2 V, -1 V, 1V, 2 V, 3 V, etc., the scanning rate is 50 mV / s, and the number of scanning segments is 2 to 12 segments, for example, 2 segments, 4 segments, 8 segments, 10 segments, 12 segments, etc.

[0035] According to an embodiment of the present disclosure, in the electrochemical deposition process, an electrochemical workstation is used and a three-electrode system is used to deposit the recording site. The recording site deposited with the above-mentioned gold nanoparticles is used as a working electrode, an Ag / AgCl electrode is used as a reference electrode, a commercially available platinum wire metal electrode is used as a counter electrode, and the working electrode is a metal electrode wire of different materials, and its materials include: gold, silver, copper, platinum iridium, platinum, stainless steel, tungsten, etc. The aqueous solution of metal nanomaterials is an electrochemical deposition solution. Adjust the electrochemical deposition parameters, and use the chronopotentiometry and cyclic voltammetry to electrochemically deposit the recording site of the pretreated metal electrode in turn. Wherein, the deposition current of the chronopotentiometry deposition is 0.001~0.1 A, for example, it can be 0.001 A, 0.005A, 0. 01A, 0.05 A, 0.1 A, etc., and the deposition time is 100~1200 s, for example, it can be 100 s, 500 s, 800 s, 1000 s, 1200 s, etc. The deposition voltage of the cyclic voltammetry method is -3~3 V, for example, -3 V, -1 V, 1 V, 2 V, 3 V, etc., the scanning rate is 50 mV / s, and the number of scanning segments is 2~12 segments, for example, 2 segments, 4 segments, 8 segments, 10 segments, 12 segments, etc. By adjusting the electrochemical deposition parameters, the deposition thickness of the metal nanomaterial can be controlled to meet the needs of neural electrodes in different application fields.

[0036] Figure 1 It is a schematic diagram of the preparation of a neural electrode in one embodiment of the present disclosure.

[0037] According to the embodiment of the present disclosure, Figure 1 As shown, the present disclosure provides a method for preparing a neural electrode, comprising the following steps:

[0038] First, use an ultrasonic cleaner to clean the surface of the metal electrode with acetone, alcohol, and deionized water in turn to remove impurities on the electrode surface, and then dry it to obtain the cleaned metal electrode. Construct a three-electrode system, using the cleaned metal electrode as the working electrode, the platinum wire metal electrode as the counter electrode, and the Ag / AgCl electrode as the reference electrode. Prepare a sulfuric acid solution as the electrolyte, and scan 50 times by cyclic voltammetry to remove the passivation layer on the surface of the metal electrode.

[0039] Then, a chloroauric acid-sulfuric acid solution is prepared as an electroplating solution, and the recording site of the metal electrode is electrochemically deposited using a chronoamperometry method to deposit gold nanoparticles on the surface of the recording site of the metal electrode to obtain a metal electrode with a recording site modified with metal nanoparticles, i.e., a pretreated metal electrode.

[0040] Using the aqueous solution of metal nanomaterial clusters as the electrodeposition solution, the metal nanomaterials are first deposited on the recording sites of the pretreated metal electrode by chronopotentiometry. The metal electrode recording sites are then cleaned and dried, and then a second deposition is performed by cyclic voltammetry to obtain metal electrode recording sites deposited with metal nanomaterials. The sites are rinsed with deionized water to remove the surface electrodeposition solution, and then dried at room temperature.

[0041] The area other than the area where the metal nanomaterials are deposited is wrapped with insulating materials to prepare a neural electrode.

[0042] According to the embodiments of the present disclosure, the thickness of the metal nanomaterial deposited on the surface of the recording site is 10 nm to 100 nm, for example, 10 nm, 30 nm, 50 nm, 70 nm, 100 nm, etc. The nanoscale deposited layer can be deposited more closely on the surface of the recording site, increase the contact area between the neural electrode and the neural tissue, and improve the sensitivity and stability of signal acquisition.

[0043] According to an embodiment of another aspect of the present disclosure, a neural electrode prepared by the above-mentioned preparation method is provided, wherein the surface of the recording site of the neural electrode is modified with metal nanomaterials.

[0044] According to the disclosed embodiment, a multiple deposition method is used to introduce bioactive metal nanomaterials into the surface of the neural electrode for modification, and the prepared neural electrode has good biocompatibility and electrical properties. It has low electrochemical impedance and excellent charge storage capacity, ensuring long-term stable signal conduction and stimulation response.

[0045] In order to make the purpose, technical scheme and advantages of the present disclosure more clear, the present disclosure is further described in detail below in conjunction with specific embodiments and drawings. Specific techniques or conditions not specified in the embodiments are conventional methods and can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0046] The counter electrodes used in the following examples and comparative examples are commercially available metal electrode wires. The metal electrodes used in the neural electrodes were purchased from WPI (World Precision Instruments Inc.), Kedou Brain Machine Technology Co., Ltd., and Kunshan Shengshi Jingxin New Materials Co., Ltd. Among them, the finished metal electrode wires below 30 μm were purchased from WPI and Kedou Brain Machine Technology Co., Ltd., and the metal electrode wires of 50 μm to 200 μm were purchased from Kunshan Shengshi Jingxin New Materials Co., Ltd.

[0047] Embodiment 1:

[0048] This embodiment 1 provides a method for preparing a neural electrode, comprising the following steps:

[0049] First, an ultrasonic cleaner was used to clean the surface of a platinum-iridium metal electrode with a diameter of 100 microns using acetone, alcohol, and deionized water for 5 minutes each to remove impurities on the electrode surface. After drying, the cleaned metal electrode was obtained.

[0050] A three-electrode system was constructed, with the cleaned metal electrode as the working electrode, a 0.5 cm diameter platinum wire metal electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. A 0.5 M sulfuric acid solution was prepared as the electrolyte, and cyclic voltammetry was performed to scan 50 cycles to remove the passivation layer on the surface of the metal electrode.

[0051] Then, a 1 mM chloroauric acid-sulfuric acid solution (based on 0.1 M sulfuric acid solvent) was prepared as the electrodeposition solution, and the chronoamperometry (CC method) was used to set a step voltage between -1 V and 0 V with a step length of 10 steps. The recording site of the metal electrode was electrochemically deposited twice to obtain a pretreated metal electrode.

[0052] Using a 0.1 mg / mL aqueous solution of manganese nanomaterial clusters as the electrodeposition solution, the metal nanomaterials were initially deposited on the recording sites of the pretreated metal electrodes by chronopotentiometry (CP method), with a deposition time of 100 s and a deposition current of 0.001 A. The metal electrode recording sites were then cleaned and dried, and then a second deposition was performed by cyclic voltammetry (CV method), with the deposition high and low voltages being -1 V and 0 V, respectively, and the number of deposition segments being 2, to obtain metal electrode recording sites deposited with metal nanomaterials. The sites were rinsed with deionized water to remove the surface electrodeposition solution, and dried at room temperature.

[0053] A polyimide insulating tube of the same diameter is used to wrap the area other than the area where the metal nanomaterials are deposited, thereby preparing a neural electrode S1.

[0054] Embodiment 2:

[0055] This embodiment 2 provides a method for preparing a neural electrode, comprising the following steps:

[0056] First, an ultrasonic cleaner was used to clean the surface of a platinum-iridium metal electrode with a diameter of 100 microns using acetone, alcohol, and deionized water for 5 minutes each to remove impurities on the electrode surface. After drying, the cleaned metal electrode was obtained.

[0057] A three-electrode system was constructed, with the cleaned metal electrode as the working electrode, a 0.5 cm diameter platinum wire metal electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. A 0.5 M sulfuric acid solution was prepared as the electrolyte, and cyclic voltammetry was performed to scan 50 cycles to remove the passivation layer on the surface of the metal electrode.

[0058] Then, a 1 mM chloroauric acid-sulfuric acid solution (based on 0.1 M sulfuric acid solvent) was prepared as the electrodeposition solution, and the chronoamperometry was used to set a step voltage between 0 V and 1 V with a step length of 20 steps. The recording site of the metal electrode was electrochemically deposited four times to obtain a pretreated metal electrode.

[0059] Using a 0.2 mg / mL aqueous solution of manganese nanomaterial clusters as the electrodeposition solution, the metal nanomaterials were initially deposited on the recording sites of the pretreated metal electrodes by chronopotentiometry, with a deposition time of 300 s and a deposition current of 0.005 A. The metal electrode recording sites were then cleaned and dried, and then a second deposition was performed by cyclic voltammetry, with the high and low voltages of 0 V and 1 V, respectively, and the number of deposition segments was 4, to obtain metal electrode recording sites deposited with metal nanomaterials. The sites were rinsed with deionized water to remove the surface electrodeposition solution and dried at room temperature.

[0060] A polyimide insulating tube of the same diameter is used to wrap the area other than the area where the metal nanomaterials are deposited, thereby preparing a neural electrode S2.

[0061] Embodiment 3:

[0062] This embodiment 3 provides a method for preparing a neural electrode, comprising the following steps:

[0063] First, an ultrasonic cleaner was used to clean the surface of a platinum-iridium metal electrode with a diameter of 100 microns using acetone, alcohol, and deionized water for 5 minutes each to remove impurities on the electrode surface. After drying, the cleaned metal electrode was obtained.

[0064] A three-electrode system was constructed, with the cleaned metal electrode as the working electrode, a 0.5 cm diameter platinum wire metal electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. A 0.5 M sulfuric acid solution was prepared as the electrolyte, and cyclic voltammetry was performed to scan 50 cycles to remove the passivation layer on the surface of the metal electrode.

[0065] Then, a 1 mM chloroauric acid-sulfuric acid solution (based on 0.1 M sulfuric acid solvent) was prepared as the electrodeposition solution, and the chronoamperometry method was used to set a step voltage between -1 V and 1 V with a step length of 50 steps. The recording site of the metal electrode was electrochemically deposited four times to obtain a pretreated metal electrode.

[0066] Using a 0.5 mg / mL aqueous solution of manganese nanomaterial clusters as the electrodeposition solution, the metal nanomaterials were initially deposited on the recording sites of the pretreated metal electrodes by chronopotentiometry, with a deposition time of 600 s and a deposition current of 0.01 A. The metal electrode recording sites were then cleaned and dried, and then a second deposition was performed by cyclic voltammetry, with the deposition high and low voltages of 1 V and 2 V, respectively, and the number of deposition segments was 8, to obtain metal electrode recording sites deposited with metal nanomaterials. The sites were rinsed with deionized water to remove the surface electrodeposition solution, and dried at room temperature.

[0067] The area other than the area where the metal nanomaterials are deposited is wrapped with a polyimide insulating tube of the same diameter to prepare the neural electrode S3.

[0068] Embodiment 4:

[0069] This embodiment 4 provides a method for preparing a neural electrode, comprising the following steps:

[0070] First, an ultrasonic cleaner was used to clean the surface of a platinum-iridium metal electrode with a diameter of 100 microns using acetone, alcohol, and deionized water for 5 minutes each to remove impurities on the electrode surface. After drying, the cleaned metal electrode was obtained.

[0071] A three-electrode system was constructed, with the cleaned metal electrode as the working electrode, a 0.5 cm diameter platinum wire metal electrode as the counter electrode, and an Ag / AgCl electrode as the reference electrode. A 0.5 M sulfuric acid solution was prepared as the electrolyte, and cyclic voltammetry was performed to scan 50 cycles to remove the passivation layer on the surface of the metal electrode.

[0072] Then, a 1 mM chloroauric acid-sulfuric acid solution (based on a 0.1 M sulfuric acid solvent) was prepared as the electrodeposition solution, and the chronoamperometry method was used to set a step voltage between 0 V and 1 V with a step length of 100 steps. The recording site of the metal electrode was electrochemically deposited four times to obtain a pretreated metal electrode.

[0073] Using a 1 mg / mL aqueous solution of manganese nanoclusters as the electrodeposition solution, the metal nanomaterials were initially deposited on the recording sites of the pretreated metal electrodes by chronopotentiometry, with a deposition time of 1200 s and a deposition current of 0.01 A. The metal electrode recording sites were then cleaned and dried, and then a second deposition was performed by cyclic voltammetry, with the deposition high and low voltages of 1 V and 3 V, respectively, and the number of deposition segments was 12, to obtain metal electrode recording sites deposited with manganese nanoclusters. The sites were rinsed with deionized water to remove the surface electrodeposition solution and dried at room temperature.

[0074] A polyimide insulating tube of the same diameter is used to wrap the area other than the area where the metal nanomaterials are deposited, thereby preparing a neural electrode S4.

[0075] Figure 2 It is a surface morphology image of the neural electrode in Example 4 of the present disclosure, wherein a is a scanning electron microscope image of the surface of the neural electrode after depositing gold nanoparticles, and b is a scanning electron microscope image of the surface of the neural electrode after further depositing manganese nanoclusters.

[0076] like Figure 2 As shown in a in the figure, gold nanoparticles are evenly covered on the surface of the metal electrode, increasing the specific surface area of ​​the electrode and significantly improving the roughness of the electrode surface. The improvement of the roughness improves the microstructure of the electrode surface and provides more active sites for electrochemical reactions, which not only facilitates the performance optimization of the substrate, but also promotes the effective deposition of subsequent metal nanomaterials. Figure 2 As shown in b, manganese nanoclusters are uniformly and densely deposited on the surface of the neural electrode, forming a tight bonding layer with the substrate, thereby reducing the obstacles to electron transmission and improving the efficiency of charge transmission.

[0077] Figure 3 It is the surface photoelectron energy spectrum of the neural electrode in Example 4 of the present disclosure, wherein a is the XPS full spectrum of the Mn cluster modified electrode, and b is the high-resolution XPS spectrum of the Mn element.

[0078] like Figure 3 As shown in a, manganese nanoclusters have been successfully deposited on the surface of the metal electrode. Figure 3 As shown in b, manganese nanoclusters are stably loaded on the surface of neural electrodes with their various valence states. Manganese in various valence states can not only enhance the biocompatibility of the electrode, but also help activate or regulate a wider range of biological signal transduction pathways, thereby showing more diverse and more efficient biological activities, providing a basis for optimizing the performance of neural electrodes as neural interfaces.

[0079] Comparative Example 1:

[0080] The non-recording site area of ​​the 100 μm platinum-iridium bare electrode surface without any treatment was coated and wrapped with polyimide insulating material to obtain the neural electrode D1.

[0081] Comparative Example 2:

[0082] The main differences between the nerve prepared in Comparative Example 2 of the present disclosure and Example 4 are as follows:

[0083] No Mn nanocluster deposition was performed on the metal electrode recording sites.

[0084] The other preparation processes in Comparative Example 2 are the same as those in Example 4, and a neural electrode D2 is prepared.

[0085] Comparative Example 3:

[0086] The main differences between the nerve prepared in Comparative Example 3 of the present disclosure and Example 4 are as follows:

[0087] No gold nanomaterial deposition was performed on the metal electrode recording sites.

[0088] The other preparation processes in Comparative Example 3 are the same as those in Example 4, and a neural electrode D3 is prepared.

[0089] Comparative Example 4:

[0090] The main differences between the nerve prepared in Comparative Example 4 of the present disclosure and Example 4 are as follows:

[0091] No gold nanomaterials were deposited on the metal electrode recording sites, while only manganese nanoclusters were deposited by chronopotentiometry.

[0092] The other preparation processes in Comparative Example 4 are the same as those in Example 4, and a neural electrode D4 is prepared.

[0093] Comparative Example 5:

[0094] The main differences between the nerve prepared in Comparative Example 5 of the present disclosure and Example 4 are as follows:

[0095] No gold nanomaterial deposition was performed on the metal electrode recording sites, while only manganese nanoclusters were deposited by cyclic voltammetry.

[0096] The other preparation processes in Comparative Example 5 are the same as those in Example 4, and a neural electrode D5 is prepared.

[0097] Comparative Example 6:

[0098] The main differences between the nerve prepared in Comparative Example 6 of the present disclosure and Example 4 are as follows:

[0099] The manganese nanoclusters were deposited only by chronopotentiometry.

[0100] The other preparation processes in Comparative Example 6 are the same as those in Example 4, and a neural electrode D6 is prepared.

[0101] Comparative Example 7:

[0102] The main differences between the nerve prepared in Comparative Example 7 of the present disclosure and Example 4 are as follows:

[0103] The deposition of manganese nanoclusters was performed only by cyclic voltammetry.

[0104] The other preparation processes in Comparative Example 7 are the same as those in Example 4, and a neural electrode D7 is prepared.

[0105] The electrochemical impedance spectroscopy (EIS) and charge storage capacity (CSC) of the neural electrodes in the embodiments and comparative examples were tested. The parameters of the electrochemical impedance test were: the test frequency range was 1 Hz~10 5 Hz, the initial voltage is the open circuit voltage, the scan rate is 10 mV / s, and the electrochemical impedance measurement value is read at 1kHz. The parameters of the cyclic voltammetry charge storage capacity test are: the electrode scan range is -0.8V~0.1V, and the scan rate is 50 mV / s.

[0106] Figure 4 It is a test diagram of the electrical performance of the neural electrodes in Example 4 and Comparative Example 1 of the present disclosure, wherein a is an electrochemical impedance spectrum diagram of the neural electrodes in Example 4 and Comparative Example 1; b is an electrochemical impedance data diagram of the neural electrodes in Example 4 and Comparative Example 1; c is a cyclic voltammetry test diagram of the neural electrodes in Example 4 and Comparative Example 1; d is a charge storage data diagram of the neural electrodes in Example 4 and Comparative Example 1.

[0107] like Figure 4 As shown in a~d in the figure, compared with the bare electrode without any deposition modification treatment in comparative example 1, the electrochemical impedance of the neural electrode in Example 4 at a frequency of 1kHz is lower, and the phase angle is close to 0°. This shows that the Faraday effect is realized on the surface of the neural electrode after the deposition of metal nanoparticles, the charge storage capacity is significantly improved, and the electrical properties of the neural electrode are effectively optimized, which is helpful for applying the neural electrode to the subsequent monitoring of electrophysiological signals.

[0108] Figure 5It is an electrical performance test diagram of the neural electrodes in Example 4, Comparative Example 1, Comparative Example 3 and Comparative Examples 6~7 of the present disclosure, wherein a is an electrochemical impedance spectrum diagram of the neural electrodes in Example 4, Comparative Example 1, Comparative Example 3 and Comparative Examples 6~7, and b is an electrochemical impedance data diagram of the neural electrodes in Example 4, Comparative Example 1, Comparative Example 3 and Comparative Examples 6~7.

[0109] Table 1 is a table of electrical performance test data of the neural electrodes in Example 4 and Comparative Examples 2 to 7 of the present disclosure.

[0110] Table 1

[0111]

[0112] like Figure 5 As shown in a~b and Table 1, the neural electrode is prepared by multiple deposition methods while introducing a gold nanoparticle layer, which can effectively reduce the electrochemical impedance of the electrode and improve the charge storage capacity. Compared with the electrode without the introduction of the gold nanoparticle layer or only using a single deposition method, the electrical performance can be comprehensively improved.

[0113] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for preparing a neural electrode, comprising: Using an aqueous solution of metal nanomaterials as an electrodeposition solution, electrochemical deposition is performed on the recording site of the pretreated metal electrode using chronopotentiometry and cyclic voltammetry in sequence to modify the metal nanomaterials on the surface of the recording site to obtain a neural electrode deposited with metal nanomaterials, wherein the metal nanomaterials are selected from one or more of manganese, gold, silver, copper, and iron.

2. The preparation method according to claim 1, further comprising: The insulating material is used to wrap the area other than the area where the metal nanomaterials are deposited.

3. The preparation method according to claim 1, wherein The metal electrode material is selected from one of platinum, platinum-iridium alloy, gold, silver, copper, tungsten, nickel-titanium alloy, and stainless steel; The diameter of the metal electrode is 2 μm~200 μm.

4. The preparation method according to claim 1, wherein The metal nanomaterial is in the form of one or more of nanoclusters, nanoparticles, single-atom nanomaterials, quantum dots, two-dimensional materials, and organic metal framework materials. The concentration of the aqueous solution of the metal nanomaterial is 0.1-1 mg / mL.

5. The preparation method according to claim 1, wherein The deposition current of the chronopotentiometry is 0.001-0.1A, and the deposition time is 100-1200s; The deposition voltage of the cyclic voltammetry method is -3~3V, the scanning rate is 50mV / s, and the number of scanning segments is 2~12 segments.

6. The preparation method according to claim 1, wherein The thickness of the metal nanomaterial deposited on the surface of the recording site is 10 nm to 100 nm.

7. The preparation method according to claim 1, wherein The pre-processing comprises: The passivation layer on the surface of the metal electrode is removed by sulfuric acid activation, and gold nanoparticles are deposited on the surface of the recording site of the metal electrode after sulfuric acid activation to obtain a pretreated metal electrode.

8. The preparation method according to claim 7, wherein: The gold nanoparticles are deposited by one or more of chronoamperometry, multi-potential step method, and cyclic voltammetry, with a total deposition number of 1 to 5 times.

9. The preparation method according to claim 2, wherein: The insulating material is selected from one of polyimide, polytetrafluoroethylene and polymethyl methacrylate.

10. A neural electrode prepared by the preparation method according to any one of claims 1 to 9, wherein: The neural electrode comprises an electrode, and a metal nanomaterial is modified on the surface of the recording site of the electrode.

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