A redox-mediator pathway for enhanced multi-colour electrochemiluminescence in aqueous solution

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• The tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3]2+) and tri-n-propylamine system is a widely used electrochemiluminescence (ECL) co-reactant.
• Enhancing the sensitivity and precision of ECL reactions is crucial for developing advanced analytical devices.

Purpose of the Study:

• To investigate the enhancement of [Ru(bpy)3]2+ co-reactant ECL using a novel iridium complex, fac-[Ir(sppy)3]3-.
• To explore the potential of fac-[Ir(sppy)3]3-* for internal standardization of ECL signals.
• To demonstrate the application of this system in low-cost, portable analytical devices.

Main Methods:

• Investigated the ECL enhancement mechanism of [Ru(bpy)3]2+ using fac-[Ir(sppy)3]3- as a redox mediator.
• Utilized the green emission of [Ir(sppy)3]3-* for internal standardization.
• Employed a digital camera to capture RGB color data for signal analysis.

Main Results:

• Achieved an order of magnitude enhancement in the co-reactant ECL reaction.
• Demonstrated successful internal standardization of [Ru(bpy)3]2+ ECL using the ratio of R and B values from RGB data.
• Showcased superior sensitivity and precision compared to existing methods.

Conclusions:

• The novel 'redox mediator' pathway involving fac-[Ir(sppy)3]3- significantly boosts ECL performance.
• Internal standardization via RGB color analysis enables robust and precise measurements.
• This approach paves the way for developing cost-effective and portable ECL analytical devices.