Developing digital PCR technologies based on wettable substrates

Since the invention of the polymerase chain reaction (PCR) in 1985, the technology has evolved from qualitative PCR to real-time fluorescent quantitative PCR (qPCR) and ultimately to digital PCR (dPCR). Notably, dPCR based on wettable substrates has attracted considerable attention and application owing to its advantages, which include automated droplet manipulation, low reagent consumption, minimal cross-contamination, and the capability for absolute nucleic acid quantification. In this review, we trace the history of PCR, with a focus on digital nucleic acid detection technologies. Subsequently, we discuss the three strategic approaches for engineering wettable substrates: surface roughening, surface modification, and surface patterning. Additionally, the application of this technology in biomedicine is introduced. Finally, we summarize the challenges facing this technology and outline future directions in materials innovation, artificial intelligence (AI)-assisted analysis, and the development of portable point-of-care testing (POCT) platforms.