A rapid in-situ synthesis of bioinspired nanoflowers on a microfluidic dipstick for point-of-care diagnosis of normoglycemic glycosuria †

Abstract

Reliable detection of urinary glucose is crucial for the early diagnosis of renal tubular dysfunctions, including normoglycemic glycosuria (NG), a condition characterized by glucose excretion despite normal blood glucose levels. Conventional urinary dipsticks lack the sensitivity required to quantify the low glucose concentrations typical of NG. Here, we present a rapid in-situ synthesis of bioinspired enzyme-copper nanoflowers directly on a paper substrate. This foundational innovation, which achieves hierarchical morphology in under 10 minutes, is integrated into a microfluidic dipstick (μDip) to create a platform for point-of-care diagnosis. The resulting bioinspired nanostructures exhibit superior catalytic activity and stability. When deployed in the μDip system comprising a 3D-printed body and a smartphone-based interface, the sensor enables ultrasensitive detection of urinary glucose across the clinically relevant range for NG (0–0.75 mM) with a detection limit of 0.017 mM, a more than 160-fold improvement over conventional strips. This facile, low-cost platform, which satisfies the ASSURED criteria for point-of-care diagnostics, offers a promising tool for decentralized screening and early renal health assessment.