Microfabricated rGO/PANI Interdigitated Electrodes for Reference-Free, Label-Free pH Sensing on Flexible Substrates.

Area of Science:

• Materials Science
• Sensor Technology
• Nanotechnology

Background:

• Flexible electronics require robust and sensitive sensing materials.
• Graphene oxide and polyaniline composites offer tunable electronic properties.
• Developing scalable microfabrication for flexible sensors is crucial for widespread adoption.

Purpose of the Study:

• To create a flexible pH sensor using reduced graphene oxide/polyaniline (rGO/PANI) composite films.
• To develop an efficient and scalable hybrid microfabrication approach for these sensors.
• To optimize the rGO/PANI composition for precise pH detection.

Main Methods:

• Hybrid microfabrication involving dip-coating rGO/PANI on polyethylene terephthalate (PET) substrates.
• Thermal reduction to form uniform composite layers with optimized PANI content (20%).
• Photolithography and oxygen-plasma etching to pattern interdigitated electrodes (IDEs) directly onto the rGO/PANI film.

Main Results:

• Successful fabrication of flexible rGO/PANI interdigitated electrode (IDE) sensors via scalable microfabrication.
• Demonstrated tunable, monotonic electrical response to pH variations across the 2-10 range.
• Identified an 80:20 rGO/PANI composition as optimal for precise pH measurements.

Conclusions:

• rGO/PANI IDEs fabricated through this method offer a scalable route to low-cost, miniaturized, and mechanically compliant pH sensors.
• The developed sensors are suitable for field and in-line monitoring applications.
• This approach simplifies sensor design by eliminating separate contact metals, reducing overall cost.