Platinum ions mediate the interactions between DNA and carbon quantum dots: diagnosis of MRSA infections

In this study, we have developed a rapid and cost-effective method employing platinum ion (Pt4+)-capped fluorescent carbon quantum dots (CQDs) coupled with loop-mediated isothermal amplification (LAMP) to detect dual MRSA genes. We synthesized nitrogen- and chlorine-co-doped fluorescent CQDs (CQDSPDs) from spermidine trihydrochlorideviaa simple one-step pyrolysis. The CQDSPDscapped with Pt4+ions through the cooperative coordination of the amine and chlorine groups on the surface of CQDs facilitated the double-stranded DNA (dsDNA)-induced fluorescence quenching of CQDs, and enabled the construction of the CQDSPDs/Pt4+probe for the detection of as few as 10 copies of the MRSA gene (mecAandfemA). The sensitivity and specificity of the CQDSPDs/Pt4+probe for MRSA detection in clinical specimens (n= 24) were 94% and 86%, respectively. Our results reveal that the CQDSPDs/Pt4+probe has great potential for the diagnosis of antibiotic-resistant superbugs with high sensitivity, specificity, and agreement. ? The Royal Society of Chemistry 2019.