Photodynamic antibacterial activity of oxidase-like nanozyme based on long-lived room-temperature phosphorescent carbon dots

In this study, a novel long-lived room-temperature phosphorescent (RTP) carbon dots (P-CDs) with the properties of ultraviolet/visible (UV/Vis) light photoresponsive oxidase-like nanozyme were synthesized from diethylene-triaminepentaacetic acid and through a one-step hydrothermal method. P-CDs were used as a light-driven oxidative-like enzyme for antimicrobial studies. The results showed that under UV/Vis light irradiation, P-CDs could efficiently convert O2 into 1O2, and the strong oxidizing property of 1O2 greatly enhanced the growth inhibition of P-CDs on Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). Meanwhile, P-CDs exhibited good photodynamic antifungal properties against Botrytis cinerea (B. cinerea). Then the P-CDs were made into P-CDs/PVA films, which effectively prolonged the preservation period of fruits under photodynamic antibacterial action. The good biocompatibility and efficient photosensitive oxygen activation can make P-CDs a more practically useful oxidase-like nanozyme.