Dual-Functional Aptasensor for the Detection and Inactivation of <i>Salmonella</i> Based on Cascade Signal Amplification Coupled with Ag–Pt Nanozymes
Qing Kang, Chenjing Ma, Junjie Liao, Qi Li, Yidi Liu, Tong Lin, Jingbo Jiao, Xinjun Du, Shuo Wang
Abstract
The establishment of a pathogen monitoring platform that integrates detection and disinfection can effectively reduce the risk of secondary pollution. Herein, we report a dual-functional aptasensor for ultrasensitive detection and efficient inactivation of Salmonella based on cascade signal amplification and nucleic-acid-templated silver–platinum (Ag–Pt) nanozymes. Specifically, in the presence of Salmonella, the method promotes an exponential amplification reaction (EXPAR) and automatic assembly circuit (AAC) reaction by aptamer targeting bacteria, accompanied by an exponentially magnified “turn-on” fluorescence. Concurrently, guided by an aptamer, Ag–Pt nanozymes attached to the surface of Salmonella can catalyze H 2 O 2 to produce reactive oxygen species and effectively inactivate Salmonella . The aptasensor shows good specificity and sensitivity, with a linear range of 2 × 10 0 –2 × 10 5 CFU/mL and a detection limit of 2 × 10 0 CFU/mL. Besides, it was applied in the detection of milk, and satisfactory results were obtained. The strategy offers a robust solution for early pathogen detection and control in food safety.