Journal of Electroanalytical Chemistry, Vol.603, No.1, 135-141, 2007
A novel boron-doped diamond (BDD)-coated platinum mesh electrode for spectroelectrochemistry
A boron-doped diamond (BDD)-coated platinum (Pt) mesh electrode has been fabricated for the first time and applied in thin-layer double-potential-step chronoabsorptometry of two high-potential redox species, Ru(bpy)(3)(3+/2+) and Fe(phen)(3)(3+/2+), in aqueous solutions. The BDD-coated mesh exhibited its characteristic as a diamond electrode by a low voltammetric background current and well-defined voltammetric responses. Moreover, in double-potential-step chronoabsorptometry with a thin-layer cell, the redox species reached a steady state rapidly and reversibly, to allow the determination of the E-0' value for Ru(bpy)(3)(3+/2+) in both alkaline (pH 8) and acidic (pH 5) solutions and for Fe(phen)(3)(3+/2+) in alkaline solutions. In contrast, on a bare Pt electrode, the, Ru(bpy)(3)(3+/2+) and Fe(phen)(3)(3+/2+) redox waves are largely buried in that of water oxidation, and spectroelectrochemical responses are highly irreversible, due probably to the attack of O-2 or OH radical on the redox species examined. The BDD-coated Pt mesh electrode will thus be an effective tool for measuring high-E-0' components in biosystems. (c) 2007 Elsevier B.V. All rights reserved.
Keywords:BDD-coated platinum mesh electrode;OTTLE spectroelectrochemistry;steady-state;[Ru(bpy)(3)](3+/2+);[Fe(phen)(3)](3+/2+)