Ag and Cu Nanoparticles Co-deposited on Nonwoven Fabric as Multi-enzyme Mimics

Owing to the considerable potential of nanozymes for antimicrobial applications, the fabrication of nanomaterials on nonwoven fabrics for fighting SARS-coronavirus 2 (SARS-CoV2) has made significant progress in industry. However, the killing mechanism of nanozymes prepared in industrial mass production is not clearly understood. In this work, a vacuum-metalized composite of Ag and Cu on either polypropylene spunbond (Ag/Cu-PPSB) or polyethylene terephthalate (Ag/Cu-PET) nonwoven fabric was investigated to determine their intrinsic enzyme-like activities. Experimental evidence indicated that Ag/Cu-PPSB exhibited oxidase-, peroxidase (POX)-, and ascorbic acid oxidase (AAO)-like activities. To further elucidate the main reactive oxygen species (ROS) generated by Ag/Cu-PPSB, specific ROS probes and EPR measurements were used to verify that hydroxyl radicals (•OH) and singlet oxygen (1O2) were both dominant in the oxidase-like reactions. Impressively, the enzyme-like activities of Ag/Cu-PPSB and Ag/Cu-PET toward the substrate o-phenylenediamine (OPD) could be applied for sensing ascorbic acid (AA) and glucose at neutral pH. This proof-of-concept study provides simple safety evaluation methods for nanocomposites fabricated in industrial mass production, which are an important prerequisite for further practical applications.