PEDOT:TOS with PEG: a biofunctional surface with improved electronic characteristics

Devices based on conducting polymers offer great promise for interfacing with cells. Here, we use vapour phase polymerisation to create a biofunctional composite material of the conducting polymer poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:TOS) and the biologically relevant poly(ethylene glycol) (PEG). On the addition of PEG, electroactivity of the PEDOT is maintained, conductivity is increased, and its performance as the active material in a transistor is unaffected. Both direct and indirect biocompatibility tests prove that PEDOT:TOS and PEDOT:TOS:PEG are biocompatible and nontoxic to mammalian cells. A functionalised PEG (PEG(COOH)) was additionally introduced into PEDOT:TOS to showcase the potential of this material for use in applications requiring biofunctionalisation.