A new paradigm in sweat based wearable diagnostics biosensors using Room Temperature Ionic Liquids (RTILs)

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Wearable diagnostic sensors require analyte stability in sweat for commercialization.
• Challenges include maintaining small analyte stability in complex sweat with variable pH and composition.

Purpose of the Study:

• To develop a facile approach for stable analyte detection in human sweat using wearable sensors.
• To demonstrate the temporal stability and continuous detection capabilities of antibody-functionalized sensors in ionic liquids (RTILs).

Main Methods:

• Utilized RTILs with antibody-functionalized sensors on nanoporous, flexible polymer membranes.
• Employed infrared spectroscopy, dynamic light scattering, and impedimetric spectroscopy for temporal stability studies.
• Assessed sensor performance for Interleukin-6 (IL-6) and Cortisol detection in human sweat.

Main Results:

• Achieved stable detection of IL-6 and Cortisol in human sweat using RTIL-based sensors.
• Demonstrated low limits of detection for IL-6 (0.2 pg/mL at 0-24 hours, 2 pg/mL at 24-48 hours).
• Confirmed continuous IL-6 detection for 10 hours and combinatorial IL-6/Cortisol detection for 48 hours with minimal cross-talk.

Conclusions:

• The developed RTIL-based antibody-functionalized sensors offer a stable and reliable platform for wearable sweat diagnostics.
• This approach addresses key challenges in maintaining analyte stability for prolonged monitoring of biomarkers like IL-6 and Cortisol.