2D AuPd alloy nanosheets: one-step synthesis as imaging-guided photonic nano-antibiotics

The complicated synthesis and undesirable biocompatibility of nanomaterials hinder the synergistic photothermal/photodynamic therapy for bacterial infections. Herein, we develop a one-step preparation method of 2D AuPd alloy nanosheets as imaging-guided photonic nano-antibiotics. 2D AuPd alloy nanosheets with an extremely small thickness (∼1.5 nm) exhibit prominent photothermal effects (η = 76.6%), excellent ROS generation, strong photoacoustic signals and desirable biocompatibility. AuPd nanosheets can eliminate 100% of representative Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) when irradiated using an 808 nm laser at 1 W cm^-2 for 5 minutes. After being modified with a bacterial targeting peptide, under the guidance of photoacoustic imaging, AuPd nanosheets achieve promising synergistic photothermal/photodynamic therapeutic efficacy in treating Staphylococcus aureus infected mice. This work expands the biomedical application of 2D noble metal nanomaterials to the field of photonic nano-antibiotics.