Amino acid-mediated chiral Ag@Au with circularly polarized light induced photothermal and photodynamic synergistic photocatalytic disinfection

As the deterioration of the environment, microbiological contamination of drinking water is threatening human health. Therefore, it is crucial to investigate rapid, reliable, and safe sterilization techniques. In this study, chiral Ag@Au nanoparticles (L/D-NPs) were synthesized using an amino acid-mediated protocol. The L/D-NPs demonstrated outstanding photothermal and photodynamic capabilities when irradiated with linearly polarized (LP) light. The photothermal and photodynamic synergism demonstrated by L/D-NPs resulted in high sterilization capability against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). It was noteworthy that these results were chirality-independent. With the interaction of chirality-matched circularly polarized light (CPL) and chiral NPs, excellent sterilization performance could be achieved even at a much lower concentration. The mechanisms were investigated using Finite-Difference Time-Domain (FDTD) simulations and photocurrent-time measurements. In addition, under identical conditions, chiral NPs were found to maintain excellent sterilization performance for the complex microbial system of actual river water. This work offers novel guidance and insights into photocatalytic disinfection, including sterilization of water and public facilities.