Nafion/Multiwalled Carbon Nanotubes/Mesoporous Silica Composite Modified Glassy Carbon Electrode for the Simultaneous Electrochemical Determination of Indigo Carmine and Carbendazim by Differential Pulse Voltammetry

A simple and reliable method based on a composite of Nafion (Naf), multiwalled carbon nanotubes (MWCNTs), and mesoporous silica (SBA-15) modified glassy carbon electrode (GCE) is reported for individual and simultaneous determination of indigo carmine (IC, dye) and carbendazim (CBZ, pesticide). SBA-15 was synthesized and characterized and used to design a GCE/Naf/MWCNTs/SBA-15 sensor, which was characterized by electrochemical techniques and used for the determination of IC and CBZ. Using the optimum conditions for differential pulse voltammetry (DPV), the peak currents were linear from 1.0 & mu;M to 11.0 & mu;M. The limits of detection for individual measurements were 0.50 & mu;M and 0.57 & mu;M for IC and CBZ, respectively, while those for simultaneous detection were 0.28 & mu;M and 0.30 & mu;M. The interferences studies show that GCE/Naf/MWCNTs/SBA-15 exhibited excellent selectivity. The developed procedure was successfully applied to determine IC and CBZ in spring, tap, and lake water.