A wearable fluorescence sensor for real-time on-body monitoring of catheter-associated urinary tract infections

We present a wearable, fluorescence-based sensor for continuous monitoring of Escherichia coli (E. coli) in catheter bags, designed for the early detection of catheter-associated urinary tract infections (CAUTIs). The system uses a flexible circuit board integrated with UV LEDs and a gray-color sensor to detect fluorescence generated by the endogenous enzymatic activity of E.coli on the MUG substrate. Data is transmitted via Bluetooth to a smartphone application, enabling real-time, cloud-independent analysis. The device detected E. coli concentrations from 100 to 10⁵ CFU/mL within 9 to 3.5 hours, respectively, and demonstrated high specificity against other common pathogens, including Staphylococcus epidermidis, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In vitro bladder model testing further validated its practical use in realistic conditions. At a cost of ~$47 and a weight of only 72 g, this platform provides a cost-effective, portable solution for early CAUTI detection in both clinical and home settings.