Fabrication and electrochemical study of K(1,10-(1,4 Butanediyl) dipyridinium)(2)[PW11O39Co(H2O)]/MWCNTs-COOH nanohybrid immobilized on glassy carbon for electrocatalytic detection of nitrite

摘要

A nanocomposite modified glassy carbon electrode (GCE) based on K(1,10-(1,4-Butanediyl) dipyridinium)2[PW11O39Co(H2O)]/carboxyl functionalized multi-walled Carbon Nanotubes ((bdpy)PW11Co/ MWCNTs-COOH/GCE) was fabricated by electrodeposition method. TEM images demonstrated that ((bdpy) PW11Co nanoparticles were dispersed uniformly on the surfaces of MWCNTs-COOH or their interlayers with a diameter of 8.5 nm. The morphological, electrochemical, and electrocatalytic behaviors of the modified electrode were investigated by field emission scanning electron microscopy (FE-SEM) combined with energy-dispersive X-ray spectroscopy, cyclic voltammetry, and amperometry techniques. The FE-SEM images well showed immobilization of (bdpy)PW11Co/MWCNTs-COOH on GCE by deformation of the mirror surface to the rough surface. The electrochemical test results confirmed that (bdpy)PW11Co/MWCNTs-COOH/GCE has good stability and remarkable electrocatalytic behavior toward the reduction of nitrite ion. The proposed sensor displayed a linear range of 10?1600 ?mol L?1 with LOD of 0.63 ?mol L?1 (S/N = 3), and sensitivity 17.9 ?A mM?1. Moreover, the results of the electrochemical experiments indicated that this sensor has an excellent selectivity, good reproducibility, and repeatability, high stability, as well as analytical performance in real samples.