Rapid real-time recirculating PCR using localized surface plasmon resonance (LSPR) and piezo-electric pumping.

Rapid detection and characterization of pathogens in patients with bloodstream infections (BSIs) is a persistent problem for modern medicine, as current techniques are slow or provide incomplete diagnostic information. Real-time polymerase chain reaction (qPCR) allows specific detection of a wide range of targets and quantification of pathogenic burdens to aid in treatment planning. However, new technological advances are required for a rapid and multiplex implementation of qPCR in clinical applications. In this paper, the feasibility of a novel microfluidic platform for qPCR is presented, integrating highly sensitive, label-free localized surface plasmon resonance (LSPR) imaging of DNA hybridization into a recirculating chip design for real-time analysis. Single target and multiplex detection of DNA target amplification are demonstrated, with a limit of detection of 5 fg μL-1 of E. coli DNA for single target PCR, correlating with approximately 300 bacteria per mL. The results of this study demonstrate the potential of this platform for simultaneous real-time detection of multiple target genes within 15 minutes that could provide live saving benefits in patients with BSIs.