Herein, an interference-free surface-enhanced Raman scattering (SERS) platform with a “sandwich” structure has been developed for reliable detection and photothermal killing of bacteria with whole blood as the real sample. The multifunctional platform comprised a plasmonic gold film (pAu) functionalized with bacteria-capturing units of 4-mercaptophenylboronic acid and internal reference of 4-mercaptobenzonitrile as the SERS substrate and vancomycin-modified core (gold)–shell (Prussian blue) nanoparticles (Au@PB@Van NPs) as the SERS tag. The detected SERS signals were from the Raman-silent region where no background signals occurred from biological sources, eliminating the interference and improving the detection sensitivity and accuracy. As a proof-of-concept, model bacterial strain, Staphylococcus aureus, was captured and detected in the whole blood samples. Furthermore, high antibacterial efficiency of approximately 100% was reached under the synergistic photothermal effect from pAu and Au@PB@Van NPs. This study provides a new avenue for bacteria detection in real samples and their subsequent in situ elimination.

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Pathogenic bacterial contamination in diverse environments seriously threatens human health. One of the most valuable approaches is to effectively combine sensitive detection with efficient sterilization to achieve source control of pathogens. Here, we constructed a nanoplatform of Bi 2 S 3 @MnO 2 @Van with targeting, photothermal, and oxidase properties for the detection and on-demand inactivation of bacteria. The Bi 2 S 3 @MnO 2 @Van nanorods (NRs) can be trapped on the surface of Gram-positive bacteria such as Staphylococcus aureus, forming a complex of Bi 2 S 3 @MnO 2 @Van/S. aureus. After being centrifuged, the suspension of Bi 2 S 3 @MnO 2 @Van NRs can catalyze the non-fluorescent Amplex Red (AR) into a fluorescent substrate and fluorescent Scopoletin (SC) into a non-fluorescent substrate. Thus, a ratiometric fluorescent sensor was constructed for the sensitive detection of bacteria with the fluorescent intensity ratio (SC/AR) as a readout, which improves anti-interference capability and can be used in real sample detection. The detection limit reaches as low as 6.0 CFU/mL. Meanwhile, the sediment contains Bi 2 S 3 @MnO 2 @Van/S. aureus where the bacteria can be effectively inactivated, thanks to the excellent photothermal property of Bi 2 S 3 @MnO 2 @Van NRs under near-infrared irradiation. The antibacterial efficiency reaches as high as 99.1%. The investigation provides an effective way for sensitive detection and highly efficient killing of pathogenic bacteria with a universal platform.