Electrogenerated Chemiluminescence. 50. Electrochemistry and Electrogenerated Chemiluminescence of Micelle Solubilized Os(bpy)32+

Abstract

The oxidative electrochemistry and electrogenerated chemiluminescence (ECL) of Os(bpy)32+ were studied in the presence of sodium dodecyl sulfate (SDS), Triton X-100, and cetyltrimethylammonium bromide (CTAB) in aqueous solutions. Variation of supporting electrolyte (NaCl) concentration affected the interaction between Os(bpy)32+ and the surfactants. The measurement of oxidation peak current (ipa) and ECL intensity at different NaCl concentrations suggested a strong interaction of Os(bpy)32+ with SDS. Above the critical micelle concentration (cmc) the strong hydrophobic interaction of Os(bpy)32+ and the SDS micelle core greatly suppresses both ipa and the ECL intensity. The interaction of Os(bpy)32+ with CTAB micelle is much weaker because of electrostatic effects. Triton X-100 micelles do not interact with Os(bpy)32+.