Au Hierarchical Nanostructure-Based Surface Modification of Microelectrodes for Improved Neural Signal Recording.

Area of Science:

• Neuroscience
• Materials Science
• Biomedical Engineering

Background:

• Microelectrodes are crucial for high-resolution neural signal recording.
• Smaller microelectrodes, while offering higher resolution, suffer from increased impedance and noise.
• Improving the signal-to-noise ratio (SNR) is essential for effective neural signal analysis.

Purpose of the Study:

• To develop a method for reducing microelectrode impedance and noise.
• To enhance the electrochemical surface area (ECSA) of microelectrodes.
• To improve the SNR of neural signals recorded by microelectrodes.

Main Methods:

• Fabrication of an Au hierarchical nanostructure (AHN) on microelectrode surfaces via electrochemical deposition.
• Characterization of AHN-modified microelectrodes using electrochemical impedance spectroscopy (EIS) and equivalent circuit modeling.
• In vitro cytotoxicity evaluation and in vivo neural signal recording in rats.

Main Results:

• The AHN-modified microelectrode demonstrated an average 80% improvement in impedance compared to bare electrodes.
• EIS analysis confirmed increased ECSA due to the AHN.
• In vivo experiments showed a 9.79 dB improvement in SNR for AHN-modified electrodes.

Conclusions:

• The AHN surface modification effectively reduces microelectrode impedance and noise, enhancing SNR.
• The developed method is a versatile post-treatment applicable to various microelectrode types.
• This technology holds promise for advancing neural signal acquisition in research and clinical applications.