Fast Screening of Urinary Tract Infections Using a Nitrite-Responsive Smartphone Fluorescent Sensor

Rapid and accurate screening for urinary tract infections (UTIs) is crucial for effective treatment, yet traditional urine culture methods are slow and resource-intensive. This study presents NH 2 -TPE-SPy , a novel nitrite-responsive fluorescent probe designed for rapid UTI screening. By leveraging nitrite-mediated fluorescence quenching through diazonium salt formation, NH 2 -TPE-SPy demonstrates high sensitivity and selectivity for nitrite detection, even in complex biological matrices. Integrated into a smartphone-compatible point-of-care testing (POCT) platform, the probe enables rapid, cost-effective, and user-friendly UTI screening, yielding results within minutes. Evaluation using simulated and clinical urine samples revealed a sensitivity of 78.18% and a specificity of 86.02%, suggesting its potential as a reliable preliminary diagnostic tool, particularly for resource-limited settings. This POCT system facilitates prompt screening, informs timely clinical decisions, and may help mitigate the overuse of empirical antibiotics. Further research will explore the applicability of NH 2 -TPE-SPy to other diagnostic markers, broadening its clinical diagnostic potential.