Carbon optically transparent electrodes for electrogenerated chemiluminescence

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Electrogenerated chemiluminescence (ECL) is a powerful analytical technique.
• Transparent electrodes are crucial for ECL detection, but conventional options like ITO have limitations.
• Carbon-based electrodes offer potential alternatives due to their unique electrochemical properties.

Purpose of the Study:

• To investigate the suitability of pyrolyzed photoresist film (PPF)-based carbon optically transparent electrodes (C-OTEs) for ECL.
• To compare the performance of C-OTEs with traditional electrodes like glassy carbon (GC) and indium tin oxide (ITO).
• To evaluate C-OTEs in both oxidative-reductive and reductive-oxidative ECL modes.

Main Methods:

• Fabrication of C-OTEs from PPF with varying thicknesses.
• Simultaneous cyclic voltammetry (CV) and ECL transient measurements.
• Electrode characterization and comparison in front-face and transmission cell geometries.

Main Results:

• PPF-based C-OTEs exhibited comparable ECL activity to GC electrodes.
• C-OTEs showed superior performance to ITO in reductive-oxidative ECL due to ITO's electrochemical instability.
• PPFs demonstrated positive potential shifts in oxidation and ECL peaks, attributed to their nanoscale thickness and internal resistance.

Conclusions:

• C-OTEs are promising for ECL applications, offering higher ECL than ITO in both modes.
• C-OTEs exhibit enhanced stability in alkaline solutions and a wide potential window.
• Tunable transparency of C-OTEs allows for more efficient ECL detection.