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Updated: Sep 29, 2025
Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water
Published on: June 9, 2014
SERS-based CRISPR/Cas assay on microfluidic paper analytical devices for supersensitive detection of pathogenic
Jianwen Zhuang1, Zhiying Zhao1, Kai Lian2
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 & Technology, Tianjin, 300457, China.
Abstract:
Rapid and point-of-need (PON) detection of bacteria is crucial to directly provide rapid and reliable diagnostics information during on-site tests, allowing more room for taking proactive measures. By taking the multifaceted advantages of CRISPR/Cas12a and surface-enhanced Raman scattering (SERS), for the first time, we designed a recombinase polymerase amplification (RPA)-integrated microfluidic paper-based analytical device (μPAD), coined RPA-Cas12a-μPAD for supersensitive SERS detection. Single-stranded DNAs were designed to "pull down" SERS nanoprobes. The amplicons of the invA gene triggered the trans-cleavage of Cas12a, resulting in the indiscriminate shredding of linker ssDNA. Thus, the degree of aggregation of SERS nanoprobes was dependent on the concentration of Salmonella typhimurium (S. typhi), which was determined on a μPAD and monitored by a Raman spectrometer. The limit of detection for S. typhi was approximately 3-4 CFU/mL for spiked milk and meat samples with a dynamic detection range from 1 to 108 CFU/mL. The RPA-Cas12a-μPAD secured accurate tests for food samples in 45 min. This work expands the reach of CRISPR-based diagnostics (CRISPR-Dx) and provides a novel and robust bacterial PON detection platform.
