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Combination of Adhesive-tape-based Sampling and Fluorescence in situ Hybridization for Rapid Detection of Salmonella on Fresh Produce
Published on: October 18, 2010
PfAgo-guided SERS signal conversion for amplification-free and semi-quantitative detection of Salmonella typhimurium
Ruibo Zhao1, Jingjing Bai1, Qiang Zhang2
1State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
Abstract:
Rapid detection of foodborne pathogens is critical for food safety. Conventional qPCR offers high sensitivity but relies on nucleic acid amplification, increasing operational complexity and false-positive risks. Here, we developed a biosensor platform named PAF-SERS (PfAgo-mediated Amplification-Free Surface-Enhanced Raman Scattering Biosensor) for detecting Salmonella typhimurium (S. typhimurium) without pre-amplification. In this platform, PfAgo specifically cleaves target DNA guided by a single-stranded DNA guide, generating a linker sequence that enables quantitative detection through SERS signal conversion. The assay completes within 55 min, with a detection limit as low as 10 CFU/mL and a linear range of 10^1 to 10^7 CFU/mL, exhibiting high specificity and reproducibility. We further applied a support vector machine (SVM) algorithm to accurately classify low-concentration samples. The method was successfully validated in milk, eggs, chicken, and feces and blood from infected mice, demonstrating its potential for rapid, on-site detection without bulky instruments.
