Decorating carbon nanotubes with nanoparticles of indium tin oxide for the voltammetric determination of metaproterenol

A voltammetric sensor prepared using a composite of multi-walled carbon nanotubes (MWCNTs) and indium tin oxide nanoparticles (ITONPs) were applied for quantifying metaproterenol in pharmaceuticals and urine samples. The characterization of the composite layer was performed using energy dispersive X-ray and scanning electron microscopic techniques. ITONPs/IVIWCNTs/GCE exhibited a great electrocatalytic effect towards the oxidation of metaproterenol with a well-defined peak at 550 mV. Compared with a number of electrodes, a GCE decorated with both MWCNTs and ITO nanoparticles also exhibited a large enhancement of voltammetric response for metaproterenol. In addition, the higher concentration of uric acid (UA) does not interfere with the selective quantification of metaproterenol. Differential pulse voltammetry (DPV) was performed for the determination of metaproterenol at ITONPs/MWCNTs/GCE. A linear plot yielding a detection limit of 1.2 x 10(-8) M was obtained for current responses of metaproterenol against concentrations in the range of 3.0 x 2.2 x 10(-5) M. The proposed modified electrode provided better voltammetric behavior, good reproducibility and long-time stability. The selective quantification of metaproterenol makes the proposed electrode of great interest for both monitoring its therapeutic use and for doping analysis. (C) 2015 Elsevier B.V. All rights reserved.