A gas-driven capillary based on the synergy of the catalytic and photothermal effect of PB@Au for Salmonella typhimurium detection

Abstract

Rapid detection method for Salmonella typhimurium is vital to prevent the spread of food-borne diseases. In this work, a gas-driven capillary detection method was established to achieve sensitive and rapid detection of Salmonella typhimurium using the catalytic and photothermal synergy of Prussian blue-nanogold (PB@Au) nanomaterials. The immuno-PB@Au probe attached to the capillary by specific identification of target bacteria catalyzed the H₂O₂ under laser irradiation, driving the H₂O₂ liquid column to move (ΔL) by producing gas, and achieving the quantitative detection of Salmonella typhimurium. After detailed optimization of the critical performance parameters of the gas-driven capillary assay, the limit of detection (LOD) after laser irradiation and being catalyzed by PB@Au was calculated to be 37 CFU mL^-1 through the determination of different concentrations of target bacteria. Furthermore, the detection performances of the gas-driven capillary method were evaluated in detail, and the recoveries ranging from 92.9 ± 4.7 % to 107.7 ± 4.1 % were achieved using the spiked actual samples with complex matrices, indicating that the established rapid assay can offer promising strategies for the monitoring and controlling of food-borne pathogenic bacteria.

Keywords: Catalysis; Gas-driven capillary assay; PB@Au; Photothermal effect; Salmonella typhimurium.