Two birds with one stone: A multifunctional nanoplatform for photothermal sensitive detection and real-time inactivation of Staphylococcus aureus with NIR responsive Cu2_XSe@Van NPs

Susceptibility point-of-care testing (POCT) and bacterial inactivation are crucial for food safety and clinical diagnosis since bacteria pose a severe hazard to public health and healthcare. To enable photothermal deter-mination and hyperthermal inactivation of bacteria, vancomycin-modified near-infrared (NIR)-responsive copper selenide nanoparticles (Cu2_XSe@Van NPs) with excellent photothermal conversion are synthesized here. Cu2_XSe@Van NPs can be trapped on the surface of Gram-positive bacteria such as Staphylococcus aureus (S. aureus), forming a Cu2_XSe@Van NPs/S. aureus complex. Suspension (Cu2_XSe@Van NPs) and sediment (Cu2_ XSe@Van NPs/S. aureus) can convert the NIR laser energy into a thermal signal that can be detected by the thermal camera at concentrations as low as 6.0 CUF mL_1. Meanwhile, S. aureus can be effectively inactivated by localized temperature rises during temperature-based signal detection. The antibacterial efficiency can reach as high as 99.53%. The proposed strategy not only provides a sensitive POCT strategy for bacterial determination but also implements efficient inactivation of bacteria simultaneously.

Automated summary

This study synthesized vancomycin-modified copper selenide nanoparticles that can be used for photothermal determination and hyperthermal inactivation of bacteria. The strategy provides a sensitive point-of-care testing method for bacterial determination and efficient bacterial inactivation.