Near Infrared-light Assisted In Situ Reduction of Antimicrobial Peptide-Protected Gold Nanoclusters for Stepwise Killing of Bacteria and Cancer Cells

Biomolecule-protected gold nanostructures show good performance in biomedical applications. However, precise control over gold nanoclusters (AuNCs) preparation with biomolecules remains challenging. Here, we develop a simple near infrared (NIR)-light assisted method for in situ reduction of antimicrobial peptide (AMP)-protected AuNCs. Take advantage of high photothermal conversion efficiency of conjugated polymer (CP) upon NIR light irradiation, we promote the rapid reduction of AuNCs by AMP at the surface of the CP. The fluorescent properties of the AuNCs were improved owing to the formation of unique Au(0)NC@Au(I)AMP core−shell nanostructure. This nanostructure is attributed to the rapid reduction of Au(0) and collision and fusion of Au(0) at high temperatures. Integrating antibacterial AMP, fluorescent AuNCs and photothermal CP, the composites facilitated different killing mechanisms for both bacteria and cancer cells. This material system provides an all-in-one strategy for stepwise killing of cancer ...