Ultrafast Photonic PCR Based on Photothermal Nanomaterials

Over the past few decades, PCR has been the gold standard for detecting nucleic acids (NAs) in various biomedical fields. However, there are several limitations associated with conventional PCR, such as complicated operation, need for bulky equipment, and, in particular, long thermocycling time. Emerging nanomaterials with photothermal effects have shown great potential for developing a new generation of PCR: ultrafast photonic PCR. Here, we review recent applications of photothermal nanomaterials in ultrafast photonic PCR. First, we introduce emerging photothermal nanomaterials and their light-to-heat energy conversion process in photonic PCR. We then review different photothermal nanomaterial-based photonic PCRs and compare their merits and drawbacks. Finally, we summarize existing challenges with photonic PCR and hypothesize its promising future research directions. Since 1983, PCR has been the gold standard for NA detection. However, progress in PCR technology is lagging, which limits its use in new applications, mainly due to its prolonged reaction time.Ultrafast photonic PCR holds great promise to significantly shorten the PCR reaction time and achieve the next PCR breakthrough after quantitative real-time PCR.Photonic PCR features volumetric heating and noncontact heating, which minimizes the energy and time consumed in heat transfer and expands the applications of NA amplification.Photothermal nanomaterials are highly efficient converters of energy from light to heat, and their large surface-to-volume ratio and uniform dispersibility enable the fast thermocycling rate of photonic PCR.