High-performance flexible potentiometric sensing devices using free-standing graphene paper

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Developing cost-effective, robust, and rugged biochemical sensing devices is crucial for point-of-care testing and on-spot monitoring.
• Graphene paper (GNP) offers unique properties as a substrate for electrochemical sensors.

Purpose of the Study:

• To report a facile approach for fabricating high-performance flexible potentiometric sensing devices using GNP electrodes.
• To investigate the transduction mechanism of GNP-based electrodes in potentiometric measurements.
• To develop and evaluate paper-type reference electrodes (RE) based on GNP.

Main Methods:

• Utilized free-standing graphene paper (GNP) as a flexible electrode substrate.
• Constructed three types of GNP-based ion-selective electrodes (GNP-ISEs).
• Developed a novel paper-type reference electrode (GNP-RE) with a photo-polymerised reference membrane directly coated onto GNP.

Main Results:

• GNP electrodes demonstrated dual functionality as electric conductors and ion-to-electron transducers.
• GNP-ISEs exhibited excellent potentiometric performance.
• The GNP-RE showed low potential variability across a wide range of biochemical species and calibration ranges.
• Integrated GNP-based sensing devices achieved performance comparable to conventional potentiometric systems.

Conclusions:

• GNP is a highly effective substrate for flexible potentiometric sensing devices.
• The developed GNP-based sensing devices offer high performance, ease of fabrication, low cost, and excellent flexibility.
• These devices are promising 'vanguard analytical tools' for routine sensing applications.