Wearable Microfluidic Electrochemical Platform Based on One-Pot Prussian Blue-Embedded Molecularly Imprinted Polymers for Simultaneous Detection of Sweat Uric Acid and Urea

Non-invasive wearable sensing of sweat uric acid (UA) and urea provides a promising strategy for early chronic kidney disease screening. Nevertheless, most electrochemical sensors for UA and urea detection suffer from insufficient anti-interference and require exogenous redox probes, restricting reagent-free on-body measurement. Herein, we develop a wearable microfluidic electrochemical platform based on Prussian blue-embedded molecularly imprinted polymer (PB-MIP) composite materials for reagent-free, enzyme-free dual-biomarker quantification. Urea-specific and UA-specific PB-MIP composites are prepared via a facile one-step ultraviolet polymerization strategy. PB uniformly embedded within the imprinted framework acts as an intrinsic solid-state redox mediator, integrating specific molecular recognition and built-in electrochemical signal transduction into a single functional material. The two PB-MIP composites are drop-coated on dual working electrodes of a screen-printed carbon electrode, coupled with a capillary-driven microfluidic chip to construct a wearable electrochemical platform. Benefiting from the microfluidic design, the system enables pump-free spontaneous collection of trace sweat samples and achieves simultaneous quantification of sweat UA and urea. The platform exhibits wide linear ranges (0.1-600 μM for uric acid, 0.1-300 mM for urea), low limits of detection, excellent anti-interference capacity, recyclability, and favorable storage stability. On-body dietary intervention tests capture clear postprandial biomarker fluctuations, and detection results show good agreement with HPLC-MS reference values. This work offers a straightforward material-engineering strategy to develop probe-free MIP sensing interfaces and integrated wearable microfluidic devices, showing promising prospects for noninvasive preliminary screening of kidney function.