S. Workman et Mm. Richter, The effects of nonionic surfactants on the tris(2,2 '-bipyridyl)ruthenium(II) - Tripropylamine electrochemiluminescence system, ANALYT CHEM, 72(22), 2000, pp. 5556-5561
The,electrochemistry and electrogenerated chemiluminescence (ECL) of Ru(bpy
)(3)(2+) (bpy =2,2'-bipyridyl) were studied in the presence of the nonionic
surfactants Triton X-100, Thesit, and Nonidet P40. The anodic oxidation of
Ru(bpy)(3)(2+) produces ECL in the presence of tri-n-propylamine in both a
queous and surfactant solutions. Increases in both ECL efficiency (greater
than or equal to8-fold) and duration of the ECL Signal were observed in sur
factant media. A shift to lower energies of the Ru(bpy)(3)(2+) ECL emission
by similar to8 nm was also observed. The one-electron oxidation Of RU(bpy)
(3)(2+) to Ru(bpy)(3)(2+) occurs at +1.03 Vvs Ag/AgCl in aqueous buffered (
0.2 M potassium phosphate) solution as found by square wave voltammetry, Th
is potential did not shift in surfactant systems, indicating that the redsh
ifts: in ECL emission are due to stabilization of ligand pi* orbitals in th
e metal-to-ligand charge-transfer excited state. These results are consiste
nt with hydrophobic interactions: :between Ru(bpy)(3)(2+) and the nonionic
surfactants.