Ultrasensitive fluorometric angling determination of Staphylococcus aureus in vitro and fluorescence imaging in vivo using carbon dots with full-color emission

Rapid, accurate, and safe screening of foodborne pathogenic bacteria is essential to effectively control and prevent outbreaks of foodborne illness. Fluorescent sensors constructed from carbon dots (CDs) and nanomaterial-based quenchers have provided an innovative method for screening of pathogenic bacteria. Herein, an ultrasensitive magnetic fluorescence aptasensor was designed for separation and detection of Staphylococcus aureus (S. aureus). Multicolor fluorescent CDs with a long fluorescent lifetime (6.73 ns) and high fluorescence stability were synthesized using a facile hydrothermal approach and modified cDNA as a highly sensitive fluorescent probe. CD fluorescence was quenched by Fe3O4 + aptamer via fluorescence resonance energy transfer (FRET). Under optimal conditions, the FRET-based aptasensor can detect S. aureus accompanied by a wide linear range of 50–107 CFU·mL–1 and a detection limit of 8 CFU·mL–1. Compared with other standard methods, this method was faster and more convenient, and the ent...