Fully integrated microfluidic devices for qualitative, quantitative and digital nucleic acids testing at point of care

Benefiting from emerging miniaturized and equipment-free nucleic acid testing (NAT) technologies, fully integrated NAT devices at point of care (POC) with the capability of “sample-in-answer-out” are proceeding at a break-neck speed to eliminate complex operations and reduce the risk of contamination. Like the development of polymerase chain reaction (PCR) technology (the standard technique for NAT), the detection signal of fully integrated NAT devices has evolved from qualitative to quantitative and recently to digital readout, aiming at expanding their extensive applications through gradually improving detection sensitivity and accuracy. This review firstly introduces the existing commercial products, and then illustrates recent fully integrated microfluidic devices for NAT at POC from the aspect of detection signals (i.e., qualitative, quantitative and digital). Importantly, the key issues of existing commercial products and the main challenges between scientific research and product development are discussed. On this basis, we envision that the MARCHED (miniaturized, automatic, reagent-preloaded, commercializable, high-throughput, environment-independent and disposable) NAT devices are expected to be realized in the near future.