Development of a microfluidic isothermal amplification nucleic acid detection (mFIND) platform for simultaneous detection of respiratory pathogens.

We developed the mFIND platform, a centrifugal microfluidic isothermal amplification system for simultaneous detection of influenza A/B (FLUAV/FLUBV), SARS-CoV-2, and RSV - key agents of acute respiratory infections. The chip integrates four independent reaction chambers preloaded with lyophilized reagents, enabling room-temperature storage and a simplified two-step workflow. A portable analyzer automates sample metering, isothermal amplification (41 ± 0.4 °C), and real-time fluorescence monitoring, completing detection within 15 min with an ultra-low reaction volume of 2.5 μL per chamber. The platform achieved limits of detection of 2 copies/test for FLUAV/FLUBV and 5 copies/test for SARS-CoV-2/RSV, with no cross-reactivity against 23 non-target pathogens. Clinical validation using 236 positive samples showed 100% positive and negative agreement with qPCR. The mFIND platform combines rapid turnaround, simplified workflow, low reagent consumption, and parallel processing of four samples (16 targets), positioning it as a practical point-of-care nucleic acid testing solution for decentralized settings.