Laser-Induced Graphene Electrodes for Flexible pH Sensors

Area of Science:

• Materials Science
• Biomedical Engineering
• Sensor Technology

Background:

• Personalized medicine relies on real-time monitoring of physiological signals.
• pH variations are critical indicators of various diseases and biological dysfunctions.
• Flexible, non-invasive sensors are needed for continuous health monitoring.

Purpose of the Study:

• To develop an innovative, flexible electrochemical pH sensor.
• To utilize laser-induced graphene (LIG) and PEDOT:PSS for enhanced pH sensing.
• To evaluate the sensor's performance for real-time physiological monitoring.

Main Methods:

• Fabrication of a flexible pH sensor using CO2 laser writing on a polyimide (Kapton) sheet to create LIG electrodes.
• Deposition of nanostructured PEDOT:PSS onto the LIG working electrode via ultrasonic spray coating.
• Characterization of sensor performance, including sensitivity, dynamic response, and repeatability across a pH range of 1-7.

Main Results:

• The flexible sensor exhibited a linear Nernstian slope of (75.6 ± 9.1) mV/pH, indicating good sensitivity.
• The sensor demonstrated immediate response and good repeatability during dynamic experiments.
• The device successfully measured open circuit potential (OCP) values corresponding to applied pH levels.

Conclusions:

• The developed flexible pH sensor is suitable for real-time monitoring in personalized medicine.
• The combination of LIG electrodes and PEDOT:PSS offers a promising approach for wearable biosensors.
• The sensor's mechanical flexibility and reliable performance support its potential for continuous health diagnostics.