Enhancing near-infrared photothermal activity through precise in-plane interface engineering in CuS–Au and CuS@Au ultrathin nanoplates for combating multidrug-resistant bacteria

Abstract

In-plane interface engineering of two-dimensional ultrathin CuS–Au and CuS@Au nanohybrids is realized, showcasing the potential in near-infrared photothermal conversion. The synthesis involves creating high-purity ultrathin CuS nanoplates, followed by controlled Au deposition on their edges in two patterns: a layer-by-layer approach for a seamless shell and an island-growth method for isolated nano-islands. This technique precisely manipulates the CuS–Au interface, enhancing their interaction and electronic structure. When irradiated with 808 nm and 1064 nm lasers at 0.4 W m⁻², the optimized CuS–Au hybrids achieve photothermal conversion efficiencies of 67.31% and 32.02%, respectively, along with outstanding photothermal stability. Finite difference time domain (FDTD) simulations suggest that attaching spherical particles to the plate edges significantly boosts electric field strength and temperature distribution under NIR light. Additionally, CuS–Au HNPs-I demonstrated remarkable efficacy in killing prevalent clinical pathogens with 10-minute exposure to near-infrared light, achieving an impressive antibacterial efficiency of over 99.9%. This study provides a versatile strategy for the in-plane interface engineering of two-dimensional hybrid nanostructures, paving the way for efficient photothermal materials.