Nanofibrous Membrane-Based Stretchable Electrochemical Sweat Sensor for pH Detection.

Area of Science:

• Materials Science
• Electrochemistry
• Biomedical Engineering

Background:

• Wearable, non-invasive sweat sensors are crucial for personal health management.
• Monitoring sweat pH offers insights into metabolism and homeostasis.
• Sensor stability and accuracy during body motion remain significant challenges.

Purpose of the Study:

• To develop a stretchable, nanofibrous membrane-based electrochemical pH-sensing electrode.
• To evaluate the sensor's sensitivity, accuracy, and stability under mechanical deformation.
• To assess the potential of the sensor for wearable applications in monitoring sweat pH.

Main Methods:

• Fabrication of a stretchable nanofibrous membrane by embedding multi-walled carbon nanotubes (MWCNT) and silver nanowires (AgNWs).
• Electrodeposition of polyaniline onto the nanofibrous membrane to create the pH-sensing electrode.
• Testing of the electrode's electrochemical performance in ionic solutions and under various mechanical strains (torsion, bending, tensile).

Main Results:

• The pH-sensing electrode exhibited high sensitivity (82.53 mV/pH) and accuracy across a pH range of 3 to 7.
• The electrode demonstrated stable sensing performance under deformations up to 30% tensile strain.
• Sensitivity remained above 70 mV/pH even after 1000 stretching cycles at 30% strain.

Conclusions:

• The developed stretchable electrochemical sensor shows excellent mechanical stability and reliable pH detection.
• This wearable sensor is a promising candidate for continuous sweat pH monitoring in personal health management.
• The sensor's resilience to deformation addresses key challenges in wearable health technology.