An antibiotic-bridged magnetic-persistent-luminescence sensor for culture-free and rapid diagnosis of bacterial urinary tract infection

Urinary tract infections (UTIs) are among the most common infectious diseases worldwide, characterized by high recurrence rates and increasing antibiotic resistance. Currently, urine culture remains the gold standard for pathogen diagnosis, yet it suffers from low sensitivity and prolonged turnaround times (16–18 h). To address these limitations, we developed a rapid and interference-free phosphorescence biosensor based on persistent luminescent nanoparticles (PLNPs), enabling accurate bacterial detection in complex clinical samples without autofluorescence or exogenous interference. Polymyxin B was conjugated with both PLNPs and magnetic nanoparticles (MNPs), forming a sandwich-structured detection system: MNPs facilitate magnetic enrichment and separation of pathogens, while PLNPs provide a stable phosphorescent signal for quantification. Using Escherichia coli as a model pathogen, the assay achieved a detection limit of 13 CFU mL −1 within 15 min. Clinical validation using 30 urine specimens showed excellent correlation with standard culture methods. This PLNP-based biosensor not only offers a promising alternative for rapid UTI diagnosis but also paves the way for personalized antimicrobial therapy management.