Synthesis of graphene supported graphene-like C₃N₄ metal-free layered nanosheets for enhanced electrochemical performance and their biosensing for biomolecules

A new strategy for the assembly of graphene-like C₃N₄ on graphene is reported. Transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) clearly demonstrated that g-C₃N₄ was successful in the reduction of GO and the immobilization of g-C₃N₄ on the graphene surface. Investigation of their electrochemical behaviour for several redox systems was conducted, which indicated the unique electron structure endows the G-g-C₃N₄ with faster transfer and proper amount of g-C₃N₄ could make G-g-C₃N₄ advantageous in terms of improving the redox current and promoting electron transfer. Finally, several electroactive biomolecules, such as uric acid (UA), norepinephrine (NE), tyrosine (Tyr), tryptophan (Trp), acetaminophen (APAP) and rutin, were used to probe the biosensing capacity of G-g-C₃N₄ films by using the cyclic voltammetric method.