Upconversion Fluorescence Nanoprobe-Based FRET for the Sensitive Determination of Shigella

Abstract

Shigella as a typical foodborne pathogen has strong survivability in the environment or food, leading to infectious diseases, yet its rapid detection technology with high selectivity and sensitivity remains challenging. In this study, complementary strand modified upconversion nanoparticles (UCNPs) can offer stable yellow-green fluorescence at 500–700 nm excited by a 980 nm laser. Importantly, Shigella aptamer modified gold nanoparticles (GNPs) formed by “Au−S” bond act as a fluorescence resonance energy transfer (FRET) donor and recognition element that can bind specifically to Shigella and significantly quench the fluorescence of complementary strand modified UCNPs. As a result, the fluorescence of our developed nanoprobe increased linearly with the increase in Shigella in a wide range from 1.2 × 102 to 1.2 × 108 CFU/mL and the detection limit was as low as 30 CFU/mL. Moreover, the fabricated upconversion fluorescence nanoprobe can achieve Shigella detection in contaminated chicken without enrichment in 1 h.

A Novel Nanoplatform Based on Biofunctionalized MNPs@UCNPs for Sensitive and Rapid Detection of Shigella

“…In addition, some novel UCNPs fluorescence biosensors have been developed for foodborne hazardous substances in foodstuff. For example, the UCNPs fluorescence nanoprobe-based fluorescence resonance energy transfer (FRET) was constructed for Shigella detection with a low detection limit of 30 CFU/mL [20]. Ouyang et al fabricated a UCNPs-MnO 2 luminescent resonance energy transfer (LRET) biosensor for carbendazim pesticide in food with high sensitivity (0.05 ng/mL) [21].…”