Electrochemically Lighting up Luminophores at Similar Low-Triggering-Potential with Mechanistic Insights.

Electrochemiluminescence (ECL) of high electrode compatibility and less electrochemical interference was conventionally envi-sioned by lowering the oxidative-potential of luminophores and/or screening luminophores with a low-oxidative-potential. Herein, an alternative was developed by employing the environmental-friendly carbohydrazide as coreactant, which enabled a serials luminophores with oxidative-reduction ECL at one similar lowered-triggering-potential, including Ru(bpy)3(2+) as well as CdTe, CdSe, CuInS2/ZnS and Au nanocrystals. Because the 8 electrons releasing process of carbohydrazide was electrochemi-cally triggered at ~0.25 V vs Ag/AgCl, the radicals generated via electrochemically oxidizing carbohydrazide could reduce the luminophores at a much lowered potential than these of traditional coreactants. All the luminophore/carbohydrazide systems exhibited one ECL process around 0.55 V, which was about 0.65 V lower than that of traditional Ru(bpy)3(2+)/tri-n-propylamine system (typically around +1.2 V,*), and even lower than the oxidative potential of some luminophores. ECL of the lumino-phore/carbohydrazide system was spectrally closed to that of corresponding luminophore/tri-n-propylamine system, maxi-mum-emission-wavelength of the low-triggering-potential ECL also could shift from 540 to 783 nm via selecting luminophores. The coreactant-screening strategy would be a favorable supplement to the expected luminophore-screening strategy for achiev-ing enhanced ECL performance. This work opened an avenue towards deeper understanding of ECL mechanism.