Au-Ag core-shell nanoparticles for simultaneous bacterial imaging and synergistic antibacterial activity

Positively charged Au@Ag core-shell structured nanoparticles display strong enhancement in two-photon photoluminescence (2PPL) and high 2PPL intensities upon aggregation on negatively charged bacterial surface. This allows for two-photon imaging of bacteria S. aureus under near-infrared (NIR) irradiation. The Au@Ag nanoparticles demonstrate excellent antibacterial activity, and NIR irradiation further increases their antibacterial effect especially against S. aureus biofilm. These Au@Ag nanoparticles hold potential as imaging and antibacterial agents.112