Wireless, Flexible, Ion-Selective Electrode System for Selective and Repeatable Detection of Sodium

Area of Science:

• Materials Science
• Electrochemistry
• Wearable Technology

Background:

• Existing film-based electrochemical sensors face challenges with electrical contact and material leakage.
• Wearable health monitors require reliable and stable biosensing capabilities.

Purpose of the Study:

• To develop a wireless, flexible film-based system for selective sodium detection.
• To address limitations of current electrochemical sensors for wearable applications.

Main Methods:

• Fabrication of a flexible, hydrophobic composite using carbon black and soft elastomer as an ion-to-electron transducer.
• Development of a film-based ion-selective electrode (ISE) with a membrane coating for enhanced stability.
• Testing of the sensor's performance in detecting sodium in saliva, evaluating sensitivity, stability, and selectivity.

Main Results:

• The developed sensor demonstrated repeatable and selective sodium detection in saliva.
• Achieved good sensitivity (56.1 mV/decade) and stability (0.53 mV/h).
• Exhibited a selectivity coefficient of sodium against potassium of -3.0, with reinforced stability upon mechanical bending.

Conclusions:

• The wireless, flexible sensor system shows significant potential for low-profile wearable applications.
• The material composite and sensor design offer cost efficiency, simplicity, and long-term stability.
• This work advances the development of reliable electrochemical sensors for continuous health monitoring.