Shaping up field-deployable nucleic acid testing using microfluidic paper-based analytical devices

Rapid, low-cost, and sensitive nucleic acid detection and quantification assays enabled by microfluidic paper-based analytical devices (mu PADs) hold great promise for point-of-care disease diagnostics and field-based molecular tests. Through the capillary action in mu PAD, flexible manipulation of nucleic acid samples can be achieved without the need for external pumps or power supplies, making it possible to fabricate highly integrated sample-to-answer devices that streamline the nucleic acid extraction, separation, concentration, amplification, and detection. To detect minute amounts of genetic materials from clinical and biological samples, it is also critical to develop sensitive signal readouts that generate physically detectable signals for in-device nucleic acid detection and/or quantification. In this review, we will focus on mu PAD approaches for the facile manipulation of nucleic acids and emerging signal transduction strategies allowing sensitive and specific nucleic acid detection in mu PAD.