Molecularly Imprinted Wearable Sensor with Paper Microfluidics for Real-Time Sweat Biomarker Analysis

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Wearable Technology

Background:

• Wearable sweat sensors are crucial for real-time, noninvasive health monitoring.
• Existing electrochemical sensors often require labels and redox probes, limiting sensitivity.
• There is a need for highly sensitive, label-free detection methods for sweat biomarkers.

Purpose of the Study:

• To develop a molecularly imprinted polymer (MIP)-based biochemical sensor for label-free, sensitive quantification of cortisol in sweat.
• To integrate this sensor with microfluidics and iontophoresis for continuous, real-time sweat analysis.
• To demonstrate the potential of MIP-based wearable sensors for monitoring various health-associated biochemical parameters.

Main Methods:

• Development of a molecularly imprinted polymer (MIP) sensor utilizing electrochemical impedance spectroscopy.
• Integration of multimodal electrochemical sensors with an iontophoresis sweat extraction module and paper microfluidics.
• Simultaneous quantification of sweat volume, secretion rate, sodium ion, and cortisol concentration.

Main Results:

• The MIP biosensor achieved sensitive and specific detection of cortisol down to 1 pM, a 1000-fold improvement over previous MIP sensors.
• The integrated system enabled real-time sweat analysis, quantifying multiple parameters without user intervention.
• The paper microfluidic modules facilitated continuous monitoring of sweat volume and secretion rate.

Conclusions:

• The developed MIP-based wearable sensor offers a highly sensitive and specific platform for label-free cortisol detection in sweat.
• This technology enables noninvasive, real-time monitoring of physiological conditions through sweat analysis.
• The MIP wearable sensor platform holds promise for extending to the detection of other critical biochemicals, including protein biomarkers and therapeutic drugs.