A novel tetragonal pyramid-shaped porous ZnO nanostructure and its application in the biosensing of horseradish peroxidase

A novel nano-sized tetragonal pyramid-shaped porous ZnO (TPSP-ZnO) structure was, for the first time, prepared with a high morphological yield by a simple polyglycol-assisted wet chemical method. It was found that the polyglycol had a significant influence on the nucleation and pore formation in the ZnO nanostructure. The OH^-concentration and the zinc counter-ion affected the morphology of the produced ZnO nanostructure. TPSP-ZnO can be used as an efficient matrix for immobilizing horseradish peroxidase (HRP) and applied to sense hydrogen peroxide (H₂O₂). Interestingly, it had better biosensing properties than solid spherical ZnO nanoparticles, which might result from the larger specific surface area of TPSP-ZnO, causing a higher HRP loading, and the tetragonal pyramid-shaped porous nanostructure having high fraction of surface atoms located on the corners and edges, resulting in an improved catalytic activity.