Current clinical practice for detecting low-concentration molecular biomarkers requires sending samples to centralized labs, leading to high costs and delays (Fig. 20.3.1). Recent developments in molecular diagnostics thus aim to enable point-of-care (POC) detection directly at or near the patient's location [1]–[2]. The most successful POC technology to date is the paper-based lateral-flow assay (LFA) [3]–[4]. Examples include pregnancy tests that sense progesterone and SARS-CoV-2 rapid antigen tests. However, paper-based assays generally provide binary results or limited quantitative accuracy. On the other hand, the miniaturization of instrumentation, such as Abbott i-Stat Alinity, has enabled accurate diagnostics in hospital settings [5]–[6]. However, these devices remain costly and unaffordable for at-home use. Integrating millimeter-sized CMOS integrated circuits with microfluidics presents a promising solution as it allows for tailored circuit optimization, multiplexed detection, and significant cost and size reductions that can fit in a pocket [7]–[8]. Recent examples include protein [9]–[10], DNA/RNA [11]–[12], and cells detection [13]–[14]. Nevertheless, the complexity of system packaging (requiring wire/flip-chip bonding) makes integrating microfluidics with more sophisticated functions challenging [15]–[17]. Additionally, syringe pumps and tubing are often required, which are both operationally unfriendly.
Keywords: {Proteins;Multiplexing;Costs;Accuracy;Point of care;Packaging;Pregnancy test;Solid state circuits;Molecular biomarkers;Microfluidics},