Dual-Mode Centrifugal Microfluidics for High-Throughput Immunoassays and Rapid Nucleic Acid Purification

A universal, dual-mode microfluidic platform is presented for high-throughput (HTP) biochemical analysis, capable of performing either enzyme-linked immunosorbent assays (ELISA) as well as rapid nucleic acid (NA) purification within a single lab-on-a-disc. Assay-specific functionality is achieved by simply coating antibodies for immunoassays or inserting glass fiber membranes for NA extraction, eliminating the need for multiple chip designs. A self-pressure-balanced zigzag distributor generates a capillary pressure gradient that enables fast and uniform reagent distribution across all 30 units with a single injection, preventing overflow and residual blockage under high-speed injection or repeated centrifugation steps. In addition, integrated siphon valves and bifurcation chambers precisely control fluid movement for incubation, washing, detection, and elution steps. In ELISA mode, the platform automates the full workflow and delivers results for 30 tests in under 1 h. In NA mode, RNA is extracted and eluted for downstream qPCR analysis. Using SARS-CoV-2 as a model, the platform demonstrates the ability to detect nucleocapsid protein via ELISA and confirm results through qPCR, enabling orthogonal validation and enhanced diagnostic reliability. This reconfigurable, dual-mode system offers a unified solution for protein and nucleic acid testing, ideally suited for scalable deployment in clinical diagnostics, outbreak response, and translational research.