Versatile sweat bioanalysis on demand with hydrogel-programmed wearables.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Wearable Technology

Background:

• Wearable sweat bioanalysis offers a non-invasive approach for disease diagnostics.
• Challenges remain in collecting representative sweat samples unobtrusively and analyzing clinically significant biomarkers.
• Existing methods often require physical stimulation (e.g., heat, exercise) for adequate sweat collection.

Purpose of the Study:

• To develop a versatile and non-invasive wearable method for sweat bioanalysis.
• To enable imperceptible sweat absorption and on-demand release for analysis.
• To demonstrate the capability for detecting both small molecules (glucose) and large molecules (cortisol) in sweat.

Main Methods:

• Utilized a thermoresponsive hydrogel capable of absorbing sweat without external stimuli.
• Integrated hydrogel modules into a wearable device for programmed electric heating to 42°C.
• Employed a microfluidic detection channel for releasing absorbed sweat or reagents.
• Performed one-step glucose detection and multi-step cortisol immunoassay.

Main Results:

• Successfully absorbed sweat imperceptibly, even at low sweat rates.
• Achieved on-demand sweat release and analysis via electric heating.
• Demonstrated successful one-hour detection of glucose and cortisol.
• Validated results against conventional blood and stimulated sweat sample analyses.

Conclusions:

• The developed thermoresponsive hydrogel-based wearable system provides a versatile platform for non-invasive sweat bioanalysis.
• The method overcomes challenges in sweat collection and enables efficient detection of key biomarkers.
• This technology shows significant potential for practical, non-invasive clinical diagnostics.