Spontaneously formation of peroxidase mimetics on CuWO4 for homogeneous and universal aptasensing platform

This study addresses the demand for high–performance aptasensing by reporting a spontaneously formed nanozyme on the surface of CuWO4 nanomaterials. The self–coordination of [Fe(CN)6]3- with CuWO4 nanomaterials led to the in situ formation of CuHCF on its surface, which demonstrated efficient peroxidase–like activity for the catalytic oxidation of the chromogenic substrate of 3,3′,5,5′-tetramethylbenzidine (TMB). This spontaneously formed nanozyme enabled its coupling with the stimuli–responsive mesoporous silica nanoparticles (MSN) molecule gates and the nuclease (DNase I) cleavage reaction assisted target recycling for achieving colorimetric aptasensing in label–free, immobilization–free, and highly amplified modes. The developed approach allowed the detection of 0.1–100 nM kanamycin (KANA) with the low detection limit of 3.5 pM, which could also satisfactorily identify the content of KANA in treated milk and lake water samples. The formed nanozyme may in principle be universally applicable for the detection of a range of targets of interest. We hope this spontaneously formed nanozyme would arouse the exploration of more ingenious nanozyme with exquisite biosensing applications.