3D graphene foam/ZnO nanorods array mixed-dimensional heterostructure for photoelectrochemical biosensing

Abstract

We combined a 3D graphene foam network with a ZnO NRs array and further introduced this mixed-dimensional heterostructure into a PEC biosensing system. The 3D graphene served as a conductive matrix and provided an extra-large spatial surface area for more effective synthesis of ZnO NRs, while the ZnO NRs array functioned as a photoactive material to generate charge carriers and provided reaction sites at the surface for glutathione (GSH) oxidation. Therefore, an elevated photoresponse as well as an improved PEC biosensing performance in the linear range from 5 to 300 μM and an estimated detection limit of 1.53 μM through 3σ were obtained due to the vast reactive surface area and efficient electron transfer of the designed photoanode. The proposed strategy verified that such a spatial bioactive platform is promising in biosensing related fields or other photoelectric energy conversion fields.