Versatile Au@Ru nanocomposites for the rapid detection of Salmonella typhimurium and photothermal sterilization

Abstract

In view of the current public health hazards of food-borne pathogens, it is urgent to develop a rapid detection method with high sensitivity, good specificity and operational convenience, as well as to determine an effective sterilization strategy. Herein, versatile gold-ruthenium nanocomposites modified with antibody (Au@Ru-pAb Ncs) have been constructed for the sensitive detection of Salmonella typhimurium (S. typhimurium) via the lateral flow immunochromatographic assay (LFIA). Au@Ru-pAb Ncs based LFIA exhibited a wide detection range from 2.9 × 10⁶ CFU/mL to 2.9 × 10¹¹ CFU/mL with the limit of detection of 9.8 × 10⁴ CFU/mL for S. typhimurium, and displayed excellent specificity. In addition, Au@Ru-pAb Ncs irradiated with 808 nm (500 mW/cm²) near-infrared light (NIR) had a significant antibacterial effect within only 5 min, attributed to its high photothermal conversion efficiency of 54.14%. Therefore, both sensitive detection of S. typhimurium and effective NIR-triggered photothermal sterilization were achieved by using versatile Au@Ru-pAb Ncs, showing great prospects in the field of pathogen detection and treatment.

Keywords: Detection; Nanocomposites; Photothermal sterilization; Salmonella typhimurium.