A polyoxometalate-based heterojunction nanozyme with peroxidase-mimic catalytic activity for sensitive biomolecule detection.

Nanozymes are a class of nanomaterials that can specifically mimic the structures and catalytic activities as well as overcome limitations of natural enzymes and have hence been considered as a competitive alternative to natural enzymes. At present, plenty of nanozymes, especially those with peroxidase (POD)-like catalytic activity, have been extensively explored for biosensing. In this work, we proposed polyoxometalate-based heterojunction GdPWO@WS nanoclusters (NCs) to exert intrinsic POD-like catalytic activity even under harsh catalytic conditions. Detailedly, GdPWO@WS NCs possessing conducive POD-like catalytic activity can oxidize chromogenic substrates into colored substances in the presence of HO. On the strength of the POD-like catalytic activity of GdPWO@WS NCs, a reliable analytical platform is then constructed after the optimization of catalytic conditions for the detection of HO, glutathione (GSH) and glucose a simple TMB colorimetric strategy. This work advances the utilization of versatile polyoxometalate-based nanomaterials for biosensing, dramatically broadening the potential applications of other nanozyme-based biosensors.