Abstract：
We described a two-step förster resonance energy transfer (FRET) system for ratiometric Staphylococcus aureus (S. aureus) detection based on a dual-recognition proximity binding-induced toehold strand displacement reactions (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 terminal 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.
摘要：
我们描述了用于比率测量金黄色葡萄球菌的两步förster共振能量转移（FRET）系统（S.金黄色葡萄球菌)基于双重识别邻近结合诱导的立足点链置换反应(TSDR)的检测。Ru(bpy)32+和铂纳米颗粒(PtNPs)标记的DNA(Ru-S3和PtNPs-S4)杂交以使得能够使用Ru(bpy)32+作为能量供体和PtNPs作为能量受体发生初级FRET。TSDR通过将盐酸万古霉素标记的S1（Van-S1）和金纳米簇标记的S2-适体（AuNC-S2-适体）与金黄色葡萄球菌整合而发生。Van-S1的单个DNA片段与Ru-S3的末端立足点结合，取代了Pt-S4，使用AuNC作为能量供体和Ru（bpy）32作为能量受体诱导了次级FRET。该两步FRET系统有效地提高了金黄色葡萄球菌的反应效率，检出限为1.0CFU/mL。此外，在检测食品样品中的金黄色葡萄球菌时获得了令人满意的结果，这表明了食品分析的巨大潜力。
