Nanoporous layer fiber biosensing platform for real time culture- and separation-free detecting bacterial pathogens and measuring their susceptibility to antibiotics

Shunyan Fang^a, Dan Song^a, Anna Zhu^b, Feng Long^a

Abstract

Simple, rapid, and sensitive detection of bacterial pathogens in environmental and clinical samples is a key requirement because of the ensuing high morbidity and mortality. In this study, a nanoporous layer fiber biosensing platform (called NFB) was developed for the rapid culture- and separation-free detection of bacterial pathogens through integrating evanescent wave fluorescence technology, the size effect of nanoporous layer, and real-time aptasensors. The in-situ etched nanoporous layer of the fiber probe can not only effectively distinguish free Cy5.5-aptasensors and Cy5.5-aptasensors bound to pathogens but also enhance evanescent wave fluorescence. NFB can selectively and sensitively quantify Escherichia coli O157:H7 and Salmonella typhimurium species in environmental and blood samples within 18 min and 32 min, respectively. NFB detected a significant increase in fluorescence when the mixture of pathogens and Cy5.5-aptasensors was exposed to antibiotics. Our results clearly demonstrated that the portable NFB can serve as a powerful tool for real time detection of pathogens and measurement of their response to antibiotics. .

Keywords: Nanopore, Bacterial pathogen, Aptamer, Fiber optic biosensor, Evanescent wave.