Electrochemical and electrogenerated chemiluminescence of clay nanoparticles/Ru(bpy)32+ multilayer films on ITO electrodes

The electrochemical and electrogenerated chemiluminescence of Ru(bpy)32+ immobilized in {clay/Ru(bpy)32+}n multilayer films by layer-by-layer assembly were investigated. The stable multilayer films of clay and Ru(bpy)32+ were assembled by alternate adsorption of negatively charged clay platelets and positively charged Ru(bpy)32+ from their aqueous dispersions. UV-vis spectroscopy, quartz crystal microbalance (QCM), cyclic voltammetry, and electrogenerated chemiluminescence (ECL) were used to monitor the immobilization of Ru(bpy)32+ and the regular growth of the {clay/Ru(bpy)32+}n multilayer films. The multilayer films modified electrode was used for the ECL detection of tripropylamine (TPA) and oxalate. The proposed novel immobilized method exhibited good stability, reproducibility and high sensitivity for the determination of TPA and oxalate, which mainly resulted from the contributing of clay nanoparticles with appreciable surface area, special structural features and unusual intercalation properties. Detection limits were 20 and 100 nM for TPA and oxalate, respectively and the linear concentration range extended from 60 nM to 0.66 mM for TPA.