A sensitive and selective voltammetric sensor based on multiwall carbon nanotubes decorated with MgCr2O4 for the determination of azithromycin

In this report, we synthesized MgCr2O4 nanoparticles and then multiwall carbon nanotubes were decorated with the MgCr2O4 nanoparticles. The characteristics of the new materials were studied with different techniques such as transmission electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy and electrochemical impedance spectroscopy. The multiwall carbon nanotubes decorated with MgCr2O4 nanoparticles were used as a new mediator for voltammetric determination of azithromycin. The oxidation peak of azithromycin was appeared at a potential of about 720 mV at a surface of the modified electrode. Differential pulse voltammetry exhibited two wide linear dynamic ranges of 0.25-4.0 and 4.0-10.0 mu mol L-1 azithromycin with a detection limit of 0.07 mu mol L-1 at pH 7.0. The influence of potential interfering compounds on the selectivity was studied. Finally, the modified electrode showed good sensitivity, selectivity and stability for the determination of azithromycin in real samples. (C) 2012 Elsevier B.V. All rights reserved.