Peroxidase-like Nanozymes for Point-of-Care SERS Sensing and Wound Healing.

The emergence of nanozymes provides a potential method for combating multidrug-resistant bacteria resulted from the abuse of antibiotics. However, in nanozyme-catalyzed systems, few studies have addressed the actual hydrogen peroxide (H 2 O 2 ) level involved in sterilization. Herein, we designed a high-efficiency peroxidase-mimicking nanozyme with surface-enhanced Raman scattering (SERS) property by assembling gold nanoparticles on single-layer Cu 2+ -C 3 N 4 (AuNP-Cu 2+ -C 3 N 4 ). The nanozyme effectively converts the low-active Raman reporter 3,3',5,5'-tetramethylbenzidine (TMB) into its oxidized form with H 2 O 2 , resulting in SERS signal changes, thereby achieving highly sensitive quantification of H 2 O 2 with limit of detection as low as 0.60 μM. More importantly, the nanozyme can specifically catalyze H 2 O 2 into antibacterial hydroxyl radicals. In vitro and in vivo evaluations demonstrate the remarkable antibacterial efficacy of the nanozyme/H 2 O 2 combination against Staphylococcus aureus (up to 99.9%), which could promote wound healing in mice and allow point-of-care monitoring the amount of H 2 O 2 participated in effective sterilization. This study not only displays great potential in combining multiple functionalities of nanomaterials for versatile bioassays but also provides a promising approach to design nanozymes for biomedical and catalytic applications.