CN115813399A - A kind of nerve electrode modified by nanomaterial and its preparation method - Google Patents

Abstract

The invention discloses a nanomaterial-modified nerve electrode and a preparation method thereof, wherein the preparation method comprises the following steps: carrying out roughening treatment and cleaning on the surface of a recording site of a nerve electrode, drying to obtain a working electrode, putting a nano material aqueous solution with the concentration of 0.5-10mg/mL serving as an electrodeposition working solution into an electrolytic cell, carrying out surface modification on the recording site of the nerve electrode, and carrying out deposition in an electrochemical deposition mode, wherein the number of deposition layers is 1-10, so that the nerve electrode modified by the nano material is obtained. According to the method, the nano material is used for modifying the recording sites of the nerve electrode, the physicochemical characteristics of the nano material are introduced into the electrode interface, and the surface of the electrode is provided with a controllable micro-nano structure so as to have a large effective reaction surface, so that the electrochemical performance and the detection sensitivity of the nerve electrode are improved.

Description

A kind of nerve electrode modified by nanomaterial and its preparation method

technical field

The invention belongs to the field of materials, and relates to a preparation method of a nerve electrode modified by a nanometer material.

Background technique

Neural electrodes are the core equipment unit of the brain-computer interface. As a diagnostic tool for nervous system diseases, they are widely used in neuroscience by recording and regulating neural electrical activities. Most central nervous system diseases, such as stroke, Parkinson's disease, and epilepsy, are closely related to abnormal brain circulation activities, requiring sensitive and biocompatible neural electrodes for timely diagnosis and treatment. Despite major breakthroughs and technological innovations in the field of neural electrodes, existing clinical metal electrodes still face a series of major challenges and limitations such as biocompatibility, acquisition sensitivity, and long-term stability. On the one hand, the EEG signal is very weak but the noise background is strong, and the signal frequency band is wide, so it is very vulnerable to 50Hz power frequency and high-frequency electromagnetic interference. Clinical metal electrodes are limited by problems such as slow electron transfer speed and limited charge injection ability, and the high impedance of the tissue-electrode interface leads to low signal-to-noise ratio and sensitivity of neural recordings. On the other hand, traditional implantable nerve electrodes are mainly rigid metals with a Young's modulus of about 10 ² GPa, such as tungsten, platinum, iridium, gold, etc. Compared with soft brain tissue with a Young's modulus of 1kPa, electrodes- There is a severe mechanical mismatch at the interface between tissues, which induces a series of inflammatory responses. In severe cases, the recording site is separated from the neuron and induces neuron death, which reduces the signal-to-noise ratio of neural recording and prevents effective neural stimulation.

Neural electrodes should not only ensure that the impedance of the electrode-tissue interface is low enough, but also make their size small enough to ensure accurate extraction of electrical signals from the target tissue, while reducing tissue damage, but the reduction in size will cause a substantial increase in impedance.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, provide a nano-material modification that improves the biocompatibility, acquisition sensitivity and long-term stability of the nerve electrode, and reduces the impedance on the premise of maintaining the original space selectivity of the nerve electrode. nerve electrodes.

The second object of the present invention is to provide a method for preparing a nanomaterial-modified nerve electrode.

Technical scheme of the present invention is summarized as follows:

A preparation method of a nanomaterial-modified nerve electrode, comprising the steps of:

(1) Roughen the surface of the recording site of the nerve electrode, rinse it with deionized water, put it into acetone and absolute ethanol for ultrasonic cleaning, and dry it;

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, which is connected to the electrochemical workstation, and the nanomaterial aqueous solution with a concentration of 0.5-10mg/mL is used as the The electrodeposition working solution is put into the electrolytic cell for deposition, the number of deposition layers is 1-10 layers, and the surface modification of the recording site of the nerve electrode is carried out;

(3) Use polyimide or parylene to insulate the other parts of the nerve electrode except the recording site to obtain a nanomaterial-modified nerve electrode.

Nanomaterials are preferably two-dimensional nanomaterials, nanoclusters or single-atom materials.

The material of the two-dimensional nanomaterial is preferably graphene, MoS ₂ or MoTe ₂ .

The nanoclusters are preferably Au nanoclusters, Ag nanoclusters, Mn nanoclusters or Pt nanoclusters.

The monoatomic material is preferably MN ₄ , and M in the MN ₄ is Fe, Cu, Rh, V, Pd, Pt, Ni, Mn, Zn, Ru, Ir, Cr, Zr, Mo, Re, Au, Cd, Tb, W, Ce or Co.

The deposition method is constant current deposition, constant voltage deposition or multi-potential step deposition.

The parameters of constant current deposition are deposition current 0.01-1mA, co-deposition time is 120-1200s.

The parameters of the constant voltage deposition are a deposition voltage of 0.1-2V, and a co-deposition time of 96-300s.

The parameters of multi-potential step deposition are deposition voltage 0.1-2V, co-deposition time 96-300s.

A nerve electrode modified by nanomaterials prepared by the above method.

Advantages of the present invention:

In the preparation method of the present invention, by introducing nanomaterials to modify the surface of the nerve electrode recording site, the contact area with the electrolyte can be increased under the premise of maintaining the original space selectivity, and the interface performance can be improved. The small size, large specific surface area, and good biocompatibility of nanomaterials can significantly accelerate the electron transport rate as electrode modification materials. Using nanomaterials to modify the recording sites of nerve electrodes, in addition to introducing the physical and chemical properties of the material itself into the electrode interface, also makes the electrode surface have a controllable micro-nano structure so as to have a large effective reaction surface and improve the electrochemical performance of nerve electrodes. , and detection sensitivity.

Description of drawings

FIG. 1 is a schematic diagram of electrodeposition in Example 1.

Figure 2 shows the structural characterization of nanomaterial modified electrodes.

Figure 3 shows the electrical properties of the nanomaterial modified electrode.

Figure 4 shows the electrical properties of the nanocluster modified electrode.

Figure 5 shows the electrical properties of the two-dimensional nanomaterial modified electrode.

Detailed ways

The present invention will be further described below by specific embodiment

Neural electrodes are commercially available, and the base material is metal or semiconductor silicon, and the metal is platinum, gold, platinum-iridium alloy, stainless steel, tungsten or copper. The single needle diameter of the nerve electrode is 2-100 microns.

Example 1

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) Roughen the surface of the recording site of the nerve electrode (commercialized diameter is 100 μm), (polish with 400 mesh sandpaper, the purpose is to activate the surface of the recording site of the nerve electrode and improve the electrochemical deposition The binding force between the film layer and the material of the nerve electrode), rinsed with deionized water, placed in acetone and absolute ethanol for ultrasonic cleaning, and dried;

(2) The electrode obtained in step (1) was used as the working electrode, the platinum electrode was used as the counter electrode, and Ag/AgCl was used as the reference electrode, connected to the electrochemical workstation, and the aqueous solution of Au nanoclusters with a concentration of 3 mg/mL was used as the The electrodeposition working solution was put into the electrolytic cell, and the multi-potential step deposition method was selected. The deposition voltage was 0.1V, and the deposition time of each layer was 24s. As shown, the electrochemically deposited film layer is obtained, and the surface modification of the recording site of the nerve electrode is carried out;

(3) Use polyimide to insulate (coat) the other parts of the nerve electrode except the recording site to obtain a nanomaterial-modified nerve electrode.

Example 2

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) Roughen the surface of the recording site of the nerve electrode (commercialized with a diameter of 100 μm), (polish with 400-grit sandpaper), rinse with deionized water, and ultrasonically clean it in acetone and absolute ethanol in turn, dry;

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode. Aqueous solution, aqueous solution of Au nanocluster, aqueous solution of Mn nanocluster, aqueous solution of Pt nanocluster are placed in the electrolytic cell as the electrodeposition working solution, and the constant voltage deposition method is selected. The deposition voltage is 0.1V, and the deposition time of each layer is 24s. Depositing, the number of deposition layers is 4 layers, and the co-deposition is 96s to obtain an electrochemical deposition film layer, and to modify the surface of the recording site of the nerve electrode;

(3) Use polyimide to insulate (coat) the other parts of the nerve electrodes except the recording site, and obtain 4 nerve electrodes modified by a kind of nanomaterial.

Example 3

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) Roughen the surface of the recording site of the nerve electrode (commercialized with a diameter of 2 μm), (polish with 400-grit sandpaper), rinse with deionized water, and ultrasonically clean it in acetone and absolute ethanol in turn, dry;

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, which is connected to the electrochemical workstation, and the aqueous solution of Mn nanoclusters with a concentration of 10 mg/mL is used as the Put the electrodeposition working solution into the electrolytic cell, select the constant current deposition method, the deposition current is 0.01mA, and the deposition time of each layer is 600s. The deposition is carried out. The number of deposition layers is 2 layers, and the total deposition time is 1200s. The electrochemical deposition film layer is obtained. Surface modification of the recording site of the electrode;

(3) Use polyimide to insulate (coat) the other parts of the nerve electrode except the recording site to obtain a nanomaterial-modified nerve electrode.

Example 4

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) with embodiment 1 step (1);

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and the Ag/AgCl is used as the reference electrode, which is connected to the electrochemical workstation, and the graphene aqueous solution with a concentration of 0.5 mg/mL is used as the electrode. The deposition working solution is put into the electrolytic cell, and the multi-potential step deposition method is selected. The deposition voltage is 2V, and the deposition time of each layer is 300s. Record the site for surface modification;

(3) Use polyimide to insulate (coat) the other parts of the nerve electrode except the recording site to obtain a nanomaterial-modified nerve electrode.

Example 5

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) Roughen the surface of the recording site of the nerve electrode (commercialized with a diameter of 100 μm), (polish with 400-grit sandpaper, rinse with deionized water, put in acetone and absolute ethanol for ultrasonic cleaning, and dry ;

(2) The electrode obtained in step (1) is used as a working electrode, the platinum electrode is used as a counter electrode, and Ag/AgCl is used as a reference electrode, which is connected to an electrochemical workstation, and _MoS with a concentration of 0.5 mg/mL aqueous solution, The MoTe ₂ aqueous solution and the graphene aqueous solution are put into the electrolytic cell as the electrodeposition working solution, and the constant voltage deposition method is selected. The deposition voltage is 2V, and the deposition time of each layer is 300s. Membrane layer to modify the surface of the recording site of the nerve electrode;

(3) Use polyimide to insulate (coat) the other parts of the nerve electrodes except the recording site, and obtain three nerve electrodes modified by a kind of nanomaterial.

Example 6

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) with embodiment 3 steps (1);

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, connected to the electrochemical workstation, and the MoTe ₂ aqueous solution with a concentration of 10mg/mL is used for electrodeposition Put the working solution into the electrolytic cell, select the constant current deposition method, the deposition current is 1mA, and the deposition time of each layer is 120s. The deposition is carried out. The number of deposition layers is 1 layer, and the electrochemical deposition film is obtained. modification;

(3) Use polyimide to insulate (coat) the other parts of the nerve electrode except the recording site to obtain a nanomaterial-modified nerve electrode.

Example 7

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) with embodiment 1 step (1);

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, which is connected to the electrochemical workstation, and the FeN _aqueous solution with a concentration of 3 mg/mL is used as the electrodeposited electrode. The working solution is put into the electrolytic cell, and the multi-potential step deposition method is selected. The deposition voltage is 0.3V, and the deposition time of each layer is 10s, and the deposition is carried out. The number of deposition layers is 10 layers, and the co-deposition time is 100s, and the electrochemical deposition film is obtained. , to modify the surface of the recording site of the nerve electrode;

(3) Insulate (coat) the parts of the nerve electrode except the recording site with parylene to obtain a nanomaterial-modified nerve electrode.

Example 8

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) with embodiment 1 step (1);

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, connected to the electrochemical workstation, and the VN ₄ aqueous solution with a concentration of 3 mg/mL is used as the electrodeposited electrode. The working solution was put into the electrolytic cell, and the constant voltage deposition method was selected. The deposition voltage was 0.3V, the deposition time of each layer was 10s, and the deposition was carried out. The number of deposition layers was 10 layers, and the co-deposition time was 100s. Surface modification of the recording site of the nerve electrode;

(3) Insulate (coat) the parts of the nerve electrode except the recording site with parylene to obtain a nanomaterial-modified nerve electrode.

Example 9

A nerve electrode modified by nanomaterials and a preparation method thereof, comprising the steps of:

(1) with embodiment 3 steps (1);

(2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, connected to the electrochemical workstation, and the MnN _aqueous solution with a concentration of 3mg/mL is used as the electrodeposited electrode. Put the working solution into the electrolytic cell, select the constant current deposition method, the deposition current is 0.1mA, and the deposition time of each layer is 60s. The deposition is carried out. The number of deposition layers is 10 layers, and the deposition time is 600s. Surface modification of the recording site;

(3) Insulate (coat) the parts of the nerve electrode except the recording site with parylene to obtain a nanomaterial-modified nerve electrode.

Experiments have shown that replacing Mn in MnN ₄ in this embodiment with Cu, Rh, Pd, Pt, Ni, Zn, Ru, Ir, Cr, Zr, Mo, Re, Au, Cd, Tb, W, Ce or Co, Others are the same as in this embodiment, and a corresponding nanomaterial-modified nerve electrode is prepared.

Experimental example:

Structural characterization and electrochemical performance test of a nanomaterial-modified nerve electrode (prepared in Example 1)

FIG. 2 is a characterization of the surface morphology and roughness of a nanomaterial-modified nerve electrode prepared in Example 1 by scanning electron microscope and atomic force microscope. Compared with the bare electrode, the nano-functional layer on the surface of the nerve electrode modified by a nano-material is uniform and dense, forming a large specific surface area at the interface and tightly combined with the substrate. The effective contact area of the electrode-tissue interface can be increased without increasing the geometric size of the electrode, and the charge transport performance of the electrode can be enhanced.

FIG. 3 is the electrical performance of the nanomaterial-modified nerve electrode (prepared in Example 1). Compared to unmodified nerve electrodes (bare electrodes), the electrochemical impedance of a nanomaterial-modified nerve electrode was reduced at a biologically relevant frequency of 1 kHz. The amplitude of the current passing through the surface of the nerve electrode modified by a nanomaterial is significantly increased, and the area surrounded by the cyclic voltammetry curve is significantly larger than that of the bare electrode, and the charge storage capacity is improved. It shows that a nerve electrode modified by nanomaterials can significantly improve the electrical performance of the bare nerve electrode due to the function of the interface modification functional layer.

Fig. 4 is the electrical performance of the nerve electrode modified by different nanoclusters prepared in Example 2,

Fig. 5 shows the electrical properties of nerve electrodes modified by different two-dimensional nanomaterials (Example 5), all of which can significantly reduce the electrochemical impedance of the nerve electrodes and significantly improve the electrical properties of the nerve electrodes.

Experiments have shown that the electrode surface morphology and roughness of a kind of nanomaterial-modified nerve electrode prepared in Examples 3, 4, 6, 7, 8, and 9 are larger than those of the bare electrode. Impedance decreases and charge storage increases.

The nerve electrode modified by the nanometer material of the present invention has excellent biocompatibility, high specific surface area and stability, and can still maintain good performance after long-term use, meeting the requirement of long-term implantation in the body.

Claims (10)

1. A preparation method for a nerve electrode modified by nanomaterials, characterized in that it may further comprise the steps: (1) Roughen the surface of the recording site of the nerve electrode, rinse it with deionized water, put it into acetone and absolute ethanol for ultrasonic cleaning, and dry it; (2) The electrode obtained in step (1) is used as the working electrode, the platinum electrode is used as the counter electrode, and Ag/AgCl is used as the reference electrode, which is connected to the electrochemical workstation, and the nanomaterial aqueous solution with a concentration of 0.5-10mg/mL is used as the The electrodeposition working solution is put into the electrolytic cell for deposition, the number of deposition layers is 1-10 layers, and the surface modification of the recording site of the nerve electrode is carried out; (3) Use polyimide or parylene to insulate other parts of the nerve electrode except the recording site to obtain a nanomaterial-modified nerve electrode. 2. The method according to claim 1, characterized in that the nanomaterials are two-dimensional nanomaterials, nanoclusters or single-atom materials. 3. The method according to claim 2, characterized in that the material of the two-dimensional nanomaterial is graphene, MoS ₂ or MoTe ₂ . 4. The method according to claim 2, characterized in that the nanoclusters are Au nanoclusters, Ag nanoclusters, Mn nanoclusters or Pt nanoclusters. 5. The method according to claim 2, characterized in that the monoatomic material is MN ₄ , and M in the MN ₄ is Fe, Cu, Rh, V, Pd, Pt, Ni, Mn, Zn, Ru , Ir, Cr, Zr, Mo, Re, Au, Cd, Tb, W, Ce or Co. 6. The method according to claim 1, characterized in that the deposition method is constant current deposition, constant voltage deposition or multi-potential step deposition. 7. The method according to claim 6, characterized in that the parameters of the constant current deposition are a deposition current of 0.01-1mA, and a co-deposition time of 120-1200s. 8. The method according to claim 6, characterized in that the parameters of the constant voltage deposition are a deposition voltage of 0.1-2V, and a co-deposition time of 96-300s. 9. The method according to claim 6, characterized in that the parameters of the multi-potential step deposition are a deposition voltage of 0.1-2V, and a co-deposition time of 96-300s. 10. A nanomaterial-modified nerve electrode prepared by the method according to any one of claims 1-9.

Images