Ultrafast photonic PCR

Abstract Nucleic acid amplification and quantification via polymerase chain reaction (PCR) is one of the most sensitive and powerful tools for clinical laboratories, precision medicine, personalized medicine, agricultural science, forensic science and environmental science. Ultrafast multiplex PCR, characterized by low power consumption, compact size and simple operation, is ideal for timely diagnosis at the point-of-care (POC). Although several fast/ultrafast PCR methods have been proposed, the use of a simple and robust PCR thermal cycler remains challenging for POC testing. Here, we present an ultrafast photonic PCR method using plasmonic photothermal light-to-heat conversion via photon–electron–phonon coupling. We demonstrate an efficient photonic heat converter using a thin gold (Au) film due to its plasmon-assisted high optical absorption (approximately 65% at 450 nm, the peak wavelength of heat source light-emitting diodes (LEDs)). The plasmon-excited Au film is capable of rapidly heating the surrounding solution to over 150 °C within 3 min. Using this method, ultrafast thermal cycling (30 cycles; heating and cooling rate of 12.79±0.93 °C s −1 and 6.6±0.29 °C s −1 , respectively) from 55 °C (temperature of annealing) to 95 °C (temperature of denaturation) is accomplished within 5 min. Using photonic PCR thermal cycles, we demonstrate here successful nucleic acid (λ-DNA) amplification. Our simple, robust and low cost approach to ultrafast PCR using an efficient photonic-based heating procedure could be generally integrated into a variety of devices or procedures, including on-chip thermal lysis and heating for isothermal amplifications.