Microfluidics-Implemented Biochemical Assays: From the Perspective of Readout

Over the past decades, microfluidics has emerged as an increasingly important tool to perform biochemical assays for diagnosis and healthcare. The precise fluid control and molecule manipulation within microfluidics greatly contribute to developing assays with simplicity and convenience. The advantages of microfluidics, including decreased consumption of reagents and samples, lower operating and analysis time, much lower cost, and higher integration and automation over traditional systems, offer a great platform to meet the needs of point-of-care applications. In this Review, versatile strategies are outlined and recent advances in microfluidics-implemented assays are discussed from the perspective of readout, because a convenient and straightforward readout is what a biochemical assay requires and the end user desires. Functions and properties arising from each readout are reviewed and the advantages and limitations of each readout are discussed together with current challenges and future perspectives.