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Updated: Jul 23, 2025
Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water
Published on: June 9, 2014
An ultrasensitive colorimetric biosensor for the detection of Gram-positive bacteria by integrating paper-based
Li Fu1, Suqi Deng1, Yimin Luo1
1Ministry of Education Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science & Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou, 510631, China.
Abstract:
Rapid screening of bacteria by low-cost and eco-friendly material-based approaches is still a major challenge. Herein, a colorimetric biosensor was designed for the ultrasensitive and rapid detection of Gram-positive bacteria. The biosensor exploited polydopamine and polyethyleneimine (PDA-PEI)-modified papers for separating bacteria and carbon dots (CDs) for selective colorimetric detection of Gram-positive bacteria. Noble metal-free CDs can target Gram-positive bacteria by binding with peptidoglycan and possess peroxidase-like activity. Thus, they can avert the step of modifying recognition probes, facilitating biosensor fabrication, and reducing the cost. This biosensor can detect S. aureus as low as 1 cfu mL-1, L. monocytogenes as low as 5 cfu mL-1, and B. subtilis as low as 9 cfu mL-1 within 55 min. In addition, a portable device was constructed to enable convenient and on-site quantitative detection of Gram-positive bacteria. The feasibility of the biosensor was verified by detecting Gram-positive bacteria in eggshell and sausage samples with recoveries ranging from 91.2% to 110%.
