Exploring the Antibacterial and Biosensing Applications of Peroxidase-Mimetic NiCuS Nanoflower.

Nanozymes, as artificial enzymes with the biological action of natural enzymes, have enormous potential in the fields of disease diagnosis, bacteriostasis, biosensing, etc. In this work, the NiCuS nanoflower was successfully synthesized through a one-step hydrothermal method. A combined strategy of Ni doping and morphology design was employed to adjust its electronic structure and active sites, endowing the NiCuS nanoflower with excellent peroxidase-like activity. Therefore, it can catalyze the decomposition of HO to generate •OH with higher antibacterial activity, establishing a broad-spectrum antibacterial system based on the NiCuS nanoflower against and , which avoids the harm of a high concentration of HO. Additionally, the colorless substrate TMB can be catalytically oxidized into blue ox-TMB via •OH. As a result, a colorimetric technique with rapid and accurate detection of ascorbic acid (AA) by the unaided eye was designed, in view of the specific inhibition effect towards the oxidation of TMB. This detection platform has a wide linear range (10~800 μM) with a low limit of detection (0.84 μM) and exhibits a satisfactory selectivity toward the detection of AA. This study sheds new light on the application of copper-containing nanozymes in the fields of biomedicine and bioassay.