Electropolymerised PEDOT:Polydopamine enables high-performance bioelectrode coatings.

Area of Science:

• Materials Science
• Electrochemistry
• Biomedical Engineering

Background:

• Conductive polymers like poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) are widely used as bioelectrode coatings.
• Existing PEDOT-based coatings require improved substrate adhesion for enhanced performance and longevity.

Purpose of the Study:

• To investigate polydopamine (PDA) as a co-ion dopant for PEDOT to improve substrate adhesion.
• To develop and characterize a novel PEDOT:PDA conductive polymer coating for bioelectrode applications.

Main Methods:

• A repeatable electropolymerization process was developed to create PEDOT:PDA coatings on gold substrates.
• Performance metrics including charge storage capacity and interface capacitance were measured.
• Sonication tests were used to evaluate substrate adhesion compared to PEDOT:PSS.

Main Results:

• PEDOT:PDA coatings exhibited performance metrics comparable to PEDOT:PSS, including a charge storage capacity of ~42 mC cm⁻² and interface capacitance of ~17.8 mF cm⁻².
• Sonication tests confirmed a significant adhesion advantage for PEDOT:PDA over PEDOT:PSS.
• The manufacturability and scalability of PEDOT:PDA coatings were demonstrated in microfabricated devices.

Conclusions:

• Polydopamine serves as an effective co-ion dopant for PEDOT, significantly improving substrate adhesion.
• The developed PEDOT:PDA conductive polymer is a promising material for advanced bioelectrode coatings.
• This research paves the way for broader applications of PDA in bioelectronic interfaces.