Rapid quantitative PCR equipment using photothermal conversion of Au nanoshell

Photothermal PCR, which exploits the photothermal conversion effect based on the plasmonic absorption resonance of metal nanoparticles, has garnered significant attention for its capacity to enable rapid diagnosis. Through the addition of gold nanoshells, known for their high photothermal conversion efficiency in the near-infrared region, to the PCR mixture, we achieved photothermal quantitative PCR while simultaneously conducting fluorescence measurements during the photothermal PCR cycle. Our photothermal quantitative PCR method expeditiously amplifies Lambda DNA while preserving its detection sensitivity, successfully amplifying the target DNA within just 25 minutes and detecting a minimum of 50 picograms of DNA. Furthermore, we demonstrated the versatility of photothermal quantitative PCR by applying it to genomic DNA extracted from Salmonella, showcasing its effectiveness with long base pairs. By leveraging the photothermal properties of gold nanoshells, our innovative approach to photothermal qPCR will pave the way for point-of-care diagnostics of nucleic acid biomarkers.