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

The classic and most widely used co-reactant electrochemiluminescence (ECL) reaction of tris(2,2 '-bipyridine)ruthenium(ii) ([Ru(bpy)(3)](2+)) and tri-n-propylamine is enhanced by an order of magnitude by fac-[Ir(sppy)(3)](3-) (where sppy = 5 '-sulfo-2-phenylpyridinato-C-2,N), through a novel 'redox mediator' pathway. Moreover, the concomitant green emission of [Ir(sppy)(3)](3-)* enables internal standardisation of the co-reactant ECL of [Ru(bpy)(3)](2+). This can be applied using a digital camera as the photodetector by exploiting the ratio of R and B values of the RGB colour data, providing superior sensitivity and precision for the development of low-cost, portable ECL-based analytical devices.

Automated summary

A novel 'redox mediator' pathway utilizing fac-[Ir(sppy)(3)](3-) has been discovered to significantly enhance the ECL reaction of [Ru(bpy)(3)](2+) and tri-n-propylamine. The green emission of [Ir(sppy)(3)](3-)* allows for internal standardization of the reaction, enabling superior sensitivity and precision for low-cost, portable ECL-based analytical devices when using a digital camera as the photodetector.