A novel solid-state electrochemiluminescence sensor for melamine with Ru(bpy)32+/mesoporous silica nanospheres/Nafion composite modified electrode

A novel melamine electrochemiluminescence (ECL) sensor was developed based on mesoporous SiO2 nanospheres/Ru(bpy)(3)(2+)/Nafion modified electrodes. The homogeneous mesoporous silica nanospheres, synthesized using modified Stober sal-gel process, were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET). The ECL and electrochemistry of the modified electrodes were investigated with tri-n-propylamine (TPA) as the coreactant. Furthermore, the mesporous SiO2 nanospheres/Ru(bpy)(3)(2+)-based modified electrodes were used for ECL determination of melamine. The analytical performances of this ECL sensor for melamine based on its enhancement ECL emission of Ru(bpy)(3)(2+) were investigated. The results indicated that the sensor exhibited excellent performance during melamine determination with a wide linear range (7.81 x 10(-9)-5 x 10(-6) M), low detection limit (2.6 x 10(-9) M). The high sensitivity and stability mainly resulted from the high surface area and special structure of the mesoporous silica nanospheres. The proposed ECL approach was used to analyze the melamine content in powdered milk with satisfactory results. (C) 2012 Elsevier B.V. All rights reserved.