Rapid quantitative detection system constructed via photonic PCR based on the photothermal effect of NH2-MWCNTs/TiO2

In this work, the photothermal effect of aminomodified MWCNTs/TiO₂/SiO₂/PDMS nanocomposites was utilized as a photothermal substrate to replace the metal heating block of traditional qPCR combining of the advantages of high photothermal effect of composite materials and low sample volume of static microfluidic PCR. Meanwhile, Multiple PCR rapid thermal cycles under 808 nm laser irradiation was accomplished through a non-contact energy conversion method and the use of chamber-immobilized PCR chips as specific reaction vessels. Notably, the chip chamber architecture requires merely about 8 μL of reagents compared to traditional PCR tubes. While reducing the amount of PCR reagents used, the higher specific surface area results in a larger contact surface (SSA) between the heat source and the solution. Thereafter, the CCD image sensor is then used as a fluorescence detector to monitor the amplification of the target DNA during the PCR reaction, thus enabling simultaneous fluorescence detection. In addition, the threshold cycle (Ct) value of qPCR and standard PCR curves for SARS-CoV-2 virus have been analysed in depth. Importantly, this study has important implications for the development of low-cost materials, miniaturized and portable Point-of-Care Testing (POCT) chips/systems.