Multifunctional nanoplatform for dual-mode sensitive detection of pathogenic bacteria and the real-time bacteria inactivation.

Bacterial infection is a growing public health concern and causes a huge medical and financial burden. It is of significance to efficiently construct multifunctional platforms for bacterial point-of-care testing (POCT) and elimination. Herein, near-infrared (NIR) light-responded vancomycin-doped prussian blue nanoparticles (PB-VAN) with high efficient photothermal conversion was synthesized for binding, dual-mode portable detection, and elimination of bacteria. The PB-VAN can bind to the surface of Gram-positive bacteria such as Staphylococcus aureus (S. aureus), forming complex of PB-VAN/S. aureus. After being centrifugated, the suspension solution of PB-VAN can stimulate perfluorohexane (PFH) to rapidly release oxygen (O) under NIR irradiation. Thus, the bacteria can be sensitively detected with portable pressure meter as signal reader, reporting a limit of detection (LOD) of 1.0 CFU mL. On the other side, the sediment of PB-VAN/S. aureus can be detected via thermal camera, reporting a LOD of 1.0 CFU mL. Interestingly, the bacteria can be effectively inactivated with the local temperature elevation during temperature-based detection. The antibacterial efficiency reaches as high as 99.8%. The developed multifunctional nanoplatform not only provides a straightforward "mix-then-test" way for portable detection of bacteria with high sensitivity, also realizes high efficiency elimination of bacteria simultaneously. The developed strategy was further applied for promoting wound healing of bacteria-infected mice.