Photothermal media for ultrafast photonic PCR systems: Response mechanisms, classification and development status,...

Polymerase chain reaction (PCR) nucleic acid detection technology is widely used in many fields such as disease detection and genetic testing due to its advantages of high sensitivity and high specificity. Therefore, the development of PCR-based Point of Care Testing (POCT) has attracted much attention. However, the traditional PCR instrument has the fatal defects of high cost, large volume and low efficiency, which is difficult to meet the emerging needs. The application of photothermal materials with excellent light capture and photovoltaic conversion capabilities overcomes the limitations of conventional PCR and achieves ultrafast heating rate, high sensitivity, high specificity, low cost, and miniaturization, revealing the advantages of the new generation of ultrafast PCR technology. The photothermal conversion mechanism of photothermal materials is introduced at the beginning of this review. Then, the current development of photonic PCR based on photothermal materials is systematically summarized. Between the complexity of PCR systems and the characteristics of nanoparticles, the respective advantages and shortcomings of different photothermal nanomaterials in improving PCR specificity, sensitivity and accelerating PCR are highlighted. Finally, future challenges and opportunities associated with the development of photonic PCR systems for POCT applications are outlined.