All-solid-state reference electrodes based on colloid-imprinted mesoporous carbon and their application in disposable...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Reference electrodes are crucial for electroanalytical measurements.
• Conventional reference electrodes often face limitations like instability and maintenance requirements.
• All-solid-state designs offer potential for improved performance and miniaturization.

Purpose of the Study:

• To develop and characterize novel all-solid-state reference electrodes.
• To investigate the use of colloid-imprinted mesoporous (CIM) carbon as a solid contact material.
• To demonstrate the integration of these electrodes into paper-based sensing devices.

Main Methods:

• Fabrication of all-solid-state reference electrodes utilizing CIM carbon solid contact and a poly(vinyl chloride) reference membrane.
• Doping the reference membrane with an ionic liquid and a redox couple to ensure stable interfacial potentials.
• Integration of the developed reference electrodes into disposable paper-based potentiometric sensing devices for chloride ion detection.

Main Results:

• The CIM carbon-based reference electrodes exhibited excellent resistance to light and O2.
• Potential stability was outstanding, with a potential drift as low as 1.7 μV/h over 110 h for electrodes without a redox couple.
• Successful integration into paper-based devices demonstrated compatibility with miniaturized potentiometric systems.
• Disposable paper-based Cl(-) sensing devices showed highly reproducible measurements with small sample volumes.

Conclusions:

• Colloid-imprinted mesoporous carbon is a highly stable and robust solid contact material for all-solid-state reference electrodes.
• These novel reference electrodes offer superior potential stability compared to existing technologies.
• The integration into paper-based devices provides a promising platform for inexpensive, user-friendly, and sensitive potentiometric sensing applications.