Enhanced electrochemical performance of neural electrodes based on PEDOT:PSS hydrogel

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has attracted much attention on applications of neural interfaces and other biomedical fields due to its excellent electrical performances and good biocompatibility. However, its stability still remains challenge. Here, a conductive polymer hydrogel (CPH) made from PEDOT:PSS is modified on platinum (Pt) substrate successfully through electrochemical gelation, employing copper (Cu) as the sacrificial layer. The as-prepared CPH electrode provides extensive large surface area with good adhesion after dried in the air. The uniform flower-like structure helps the electrode achieve a significantly low square impedance down to 10.09 omega cm(2) (reduction of 54.89%) at 1 kHz, compared with that of bare Pt. It exhibits a high cathodic charge storage capacity (CSCc) up to 82.36 mC cm(-2), about 27 and 16.18 times higher than that of bare Pt and PEDOT:PSS coating respectively. Besides, no obviously variation of CSCc occurs after 5 CV cycles in phosphate buffered saline (PBS), and superior charge injection capacity (CIC) was also observed. Such CPH material presents great potential for preparing functionalized flexible electrode, implying promising applications on neural implants and other flexible electronics.