Patternable Gelatin Methacrylate/PEDOT/Polystyrene Sulfonate Microelectrode Coatings for Neuronal Recording

Area of Science:

• Biomaterials Science
• Neuroscience
• Electrochemistry

Background:

• Developing soft biomaterials for neural interfaces is crucial to minimize mechanical mismatch between electronics and biological tissues.
• Existing microelectrodes often suffer from performance limitations due to this mismatch.

Purpose of the Study:

• To synthesize and characterize a novel conducting polymer hydrogel (CPH) coating for microelectrodes.
• To evaluate the material's suitability for improving neural interface performance and recording capabilities.

Main Methods:

• Electrochemical polymerization of poly(3,4-dioxythiophene)/polystyrene sulfonate (PEDOT/PSS) within a gelatin methacrylate (GelMA) hydrogel.
• Photolithographic patterning and covalent attachment to gold microelectrodes.
• Characterization using infrared spectroscopy, cyclic voltammetry, and impedance spectroscopy.
• Assessment of electrochemical stability, long-term performance, and biocompatibility with primary hippocampal neurons.

Main Results:

• A hybrid GelMA/PEDOT/PSS conducting polymer hydrogel (CPH) was successfully synthesized and patterned.
• CPH coatings exhibited reversible electroactivity, low impedance comparable to conventional PEDOT/PSS, and excellent electrochemical stability (>1000 cycles, 14 days).
• The CPH material demonstrated good biocompatibility and enabled successful recording of neuronal activity from hippocampal cells using coated microelectrode arrays (MEAs).

Conclusions:

• The developed GelMA/PEDOT/PSS CPH is a promising soft biomaterial for neural interface applications.
• This material effectively reduces mechanical mismatch and enhances microelectrode performance for neural recording.
• CPH coatings offer a viable strategy for improving the longevity and efficacy of bioelectronic devices.