AuCu-Based Solid-Hollow Hybrid Nanostructures for Efficient Photothermal Therapy against Multidrug-Resistant Bacteria

Hybrid nanostructures incorporating anisotropic structural components present promising opportunities for developing advanced photothermal agents. Here, we report the controlled synthesis of solid–hollow hybrid nanostructures based on gold–copper (Au–Cu) and demonstrate their photothermal antibacterial properties. Starting from Au nanoplate seeds, we achieve anisotropic deposition to synthesize AuCu and AuAgCu Janus nanostructures. The newly-deposited regions are subsequently transformed into porous architectures via a galvanic replacement reaction mediated by KCl and acetic acid. The introduced nanopores enhance near-infrared (NIR) absorption, thereby improving photothermal conversion efficiency under both 808 nm and 1064 nm laser irradiation and enabling the efficient eradication of multidrug-resistant bacteria. Finite-difference time-domain (FDTD) simulations confirm their optimized plasmonic properties. The current study underscores the potential of morphologically complex hybrid nanostructures for advanced photothermal applications.