Disposable stepped radial microfluidic test card for multiplex electrochemical whole-blood analysis

Diabetes, hyperuricaemia, dyslipidaemia, and related metabolic disorders often coexist, creating a need for point-of-care testing (POCT) that can analyse multiple biomarkers from a small whole-blood specimen. Most disposable electrochemical strips remain single-analyte devices and therefore require repeated sampling and separate strips. Here, we developed a disposable five-channel electrochemical test card based on a fivefold rotationally symmetric stepped radial microfluidic architecture. A 10 μL aliquot of whole blood is introduced once through the central inlet and passively distributed to four amperometric channels for glucose (Glu), uric acid (UA), total cholesterol (TC), and β-hydroxybutyrate (β-HB), together with an impedance channel for independent haematocrit (HCT) estimation. The injection-moulded substrate integrates embedded copper traces with gold-plated sensing areas and requires no pump or valve. A glucose-preloading challenge produced a mean maximum receiver-channel crosstalk of 0.675 ± 0.077%, with a highest individual value of 0.815% under the nominal loading condition. In 20 clinical whole-blood samples, test-card results correlated with the corresponding reference methods (R² = 0.9484-0.9959), and analyte-specific Bland-Altman analysis supported preliminary agreement within the tested ranges. This disposable microfluidic electrochemical test card enables comprehensive multi-metabolite analysis under POCT conditions using only 10 μL whole blood, and offers a promising technical solution for next-generation precision management of metabolic diseases and multiplex POCT systems.