Fully integrated wearable microfluidic device for molecularly imprinted electrochemical and cascade catalysis colorimetric analysis of cortisol and glucose in sweat

Wearable sensors enable non-invasive and continuous analysis of biological fluids and hold substantial significance for the realization of precise, real-time health management. In this work, a wearable microfluidic device was integrated with molecularly imprinted electrochemical sensor and cascade catalysis colorimetric sensor for real-time monitoring cortisol and glucose in human sweat. The device could realize swift and efficient collection of sweat, which avoids the sweat evaporation and simplifies the sampling process. First, Prussian blue (PB) was embedded within the molecularly imprinted polymers (MIP) layer and electropolymerized on the highly conductive metal-organic framework (MOF)-derived porous carbon nanorods (MCN) modified screen-printed electrode (SPE), and realizing highly sensitive and selective detection of cortisol with a wide linear range of 20–500 nM. Meanwhile, a Cu MOF/glucose oxidase (GOD) based nanozymatic-enzymatic cascade catalysis system was constructed in the multi-channel microfluidic chip for colorimetric detection of glucose with excellent sensitivity, selectivity, reproducibility, and stability. More importantly, the wearable sensor was utilized for real-time analysis of cortisol in volunteers’ sweat in the morning and evening, and glucose levels were measured pre- and postprandially with high accuracy. Overall, this wearable microfluidic device offers great potential in daily health management.