Two-step fo spacing diaeresis rster resonance energy transfer amplification for ratiometric detection of pathogenic bacteria in food samples

We described a two-step fo center dot rster resonance energy transfer (FRET) system for ratiometric Staphylococcus aureus (S. aureus) detection based on a dual-recognition proximity binding-induced toehold strand displacement re-actions (TSDR). Ru(bpy)32+ and platinum nanoparticles (Pt NPs) labeled DNA (Ru-S3 and Pt NPs-S4) hybridized to enable the occurrence of the primary FRET using Ru(bpy)32+ as the energy donor and Pt NPs as the energy acceptor. TSDR happened by integrating vancomycin hydrochloride labeled S1 (Van-S1) and gold nanoclusters labeled S2-aptamer (Au NCs-S2-aptamer) with S. aureus. The single DNA segments of Van-S1 bond to the ter-minal toehold of Ru-S3, displacing Pt-S4, inducing the secondary FRET using Au NCs as the energy donor and Ru (bpy)32+ as the energy acceptor. This two-step FRET system efficiently improved the reaction efficiency of S. aureus with a detection limit of 1.0 CFU/mL. Furthermore, satisfactory results obtained while detecting S. aureus in food samples, indicating a great potential for food analysis.

Automated summary

We described a two-step FRET system for ratiometric Staphylococcus aureus detection, which showed satisfactory results in food samples.