PEDOT and PEDOT:PSS conducting polymeric hydrogels: A report on their emerging applications

Conducting polymers (CP’s) are currently being explored in areas like bio-interfaces, bioelectronics and medical purposes. Inclusion of moieties of CP’s into hydrogels has received substantial traction in recent years due to their high conduction (both electrical and electrolyte phases), adjustable mechanical properties, swelling disposition and their tunable three dimensional (3D) matrix. As such conducting polymeric hydrogels (CPH’s) have successfully emerged as potential candidates for medical therapies, medical and bioelectronics, environmental pollution treatments, energy storage and sensors. CPH’s provide a better platform for envisaging innovative technologies including flexible electronic devices like supercapacitors due to the flexible nature of CPH’s. Among large class of CP’s poly (3,4-ethylenedioxythiophene) (PEDOT) has attracted huge interest in fabrication of CPH’s. PEDOT has emerged as a champion material in field of bioelectronics harboring broader domain of applications with an added advantage related to its versatile synthetic process. PEDOT in combination with Polystyrene sulfonate (PSS) (as CPH’s) shows strong potential in bioelectronics due to its high stability maintaining the redox coloration and electrical conductivity (1–10 S cm-1) of PEDOT itself and hence tuning the conducting nature of PEDOT:PSS based hydrogels is very interesting area to explore. We take this opportunity to describe chemical forms and functionalities of PEDOT based CPH’s. Finally we review PEDOT based CPH’s and enlist the applications of PEDOT based CPH’s in 3D patterning, bioelectronics, tissue engineering, drug delivery and electrode purposes.