A Finger-Actuated Microfluidic System for Point-Of-Care Detection of SARS-CoV-2 and Influenza A

The cocirculation and infection of SARS-CoV-2 and influenza A viruses significantly impact the transmission dynamics of infectious diseases and increase the public health burden on communities. Nucleic acid amplification testing (NAAT), the gold standard for pathogen detection, has been widely used in point-of-care testing (POCT). However, consumer-grade NAAT-based medical POCT products tailored to resource-limited settings remain scarce. In this study, we developed a finger-actuated visual microfluidic chip with a colorimetric detection system based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) to enable efficient and cost-effective detection of SARS-CoV-2 and influenza A. During on-site testing, 280-340 μL of oropharyngeal swab sample is first added to the microfluidic chip through a dropper. The sample is then evenly distributed across four separate reaction chambers within the chip by the force driven by finger pressure. Through quantitative and qualitative experiments, we verified the feasibility and versatility of the chip and demonstrated that this system exhibits high sensitivity, with a limit of detection (LoD) of 100 copies/μL in extraction-free devices, while effectively preventing cross-contamination between individual reaction chambers. Testing with 20 mock clinical swab samples showed that the system achieved 100% detection rate and specificity. Thus, we believe the finger-actuated microfluidic system, with its low cost, ease of use, and versatile detection capabilities, can offer a powerful POCT tool for timely viral infection confirmation during the influenza season.