Fabric-based visualization biosensor for real-time environmental monitoring and food safety

Foodborne and waterborne bacterial infections caused by Escherichia coli (E. coli) pose a serious threat to public health and safety. Therefore, there is an urgent need to develop a fast and accurate diagnostic device for early detection and prevention of bacterial contamination. In this study, we designed a visual cotton fabric-based detection biosensor that can target enzymes produced by E. coli metabolism and induce color changes. In addition, the system can be integrated with the naked eye, smartphones, and small spectrometers to analyze the generated signals for qualitative, semi-quantitative, and quantitative detection. The platform achieved a minimum detection limit of 537 cfu/mL for E. coli, a wide detection range of 10²-10⁶ cfu/mL, and a minimum detection time as low as 20 mins. The detection results of complex environmental samples showed that the system has excellent anti-ion interference and anti-pH interference behavior. This visual detection biosensor has great commercial application potential and can be widely used in real-time on-site detection due to its rapid, portable, anti-interference, and low-cost advantages.