Cu-V-Ag tri-metal mesoporous nanozyme for high-efficiency UV-vis/RGB monitoring of CrO42- and amoxicillin residue.

To monitor toxic CrO42- and amoxicillin residue efficiently, tri-metal Cu-V-Ag mesoporous nanospheres (Cu-V-Ag MNS) were identified in this work. Based on the synergistic effect among Ag0, V2O5, CuOx and bovine serum albumin (BSA), Cu-V-Ag MNS expressed outstanding oxidase-like activity to catalyze 3,3',5,5'-tetramethylbenzidine (TMB) oxidization with Vmax/Km of 0.0326 mM/2.86×10-8 M·s-1. Trace CrO42- or amoxicillin could exclusively enhance or deteriorate its oxidase-like activity with clear hyperchromic or hypochromic effect. Under optimized conditions, Cu-V-Ag MNS was applied for dual-mode UV-vis/red-green-blue (RGB) monitoring of CrO42- or amoxicillin with satisfactory relative standard deviations less than 3.78%/4.01% or 3.58%/3.92% respectively. The dual-mode monitoring reliability and sensing mechanism to CrO42- and amoxicillin were investigated in detail. This work will provide a potential to modify nature bio-macromolecules for dual-mode high-efficiency monitoring of environmental contaminations practically.