Visible Light-Driven Membraneless Photocatalytic Fuel Cell toward Self-Powered Aptasensing of PCB77.

Artificial photocatalytic systems have been extensively established to mimic the natural solar-energy conversion process for developing useful photoelectric devices. In this work, a membraneless, hydrogen peroxide (H2O2)-based photocatalytic fuel cell (PFC) operated under visible light was proposed and applied in self-powered sensing of 3,3',4,4'-tetrachlorobiphenyl (PCB77). The PFC was comprised of a photoanode fabricated with gold nanoparticles-decorated graphitic C3N4 nanosheet and a cathode modified with hemin-graphene nanocomposites. The combination of both photocatalytic oxidation and electrochemical reduction of H2O2 processes led to electron transfer in the external circuit, which could generate a certain electric power output. Taking the advantage of the inhibited output performance of PFC by PCB77 which interacted with aptamer immobilize on the photoanode, a self-powered aptasensor driven by visible light was achieved, without applying an external electric source. Thus, a highly sensitive and selective self-powered aptasensor for PCB77 was successfully demonstrated.