Three-dimensional nitrogen-doped graphene porous hydrogel fabricated biosensing platform with enhanced photoelectrochemical performance

The aggregation of photoelectrochemical (PEC) active material and biological receptors may affect PEC performances due to limited accessible surface areas. To solve the problem, here we introduced 3D nitrogen-doped graphene hydrogel (3DNGH) into PEC sensing for the first time. 3DNGH not only showed better conductivity than that of 3D graphene due to introducing nirtrogen element into graphene framework, but also provided a high loading amount for PEC active nanomaterial and biological receptors with the porous structure. ZnO/3DNGH was prepared via the hydrothermal treatment. Compared to ZnO/3DGH and ZnO/2DNG, the photocurrent under visible light was greatly improved due to the enhanced light adsorption and accelerated charge transfer. Then ZnO/3DNGH was used to immobilize enzymes to construct a PEC biosensing platform and exhibited good performances. The good result indicated 3DNGH is the promising host for developing PEC biosensors in biomedical and environmental analysis.