Development of a nano-modified glassy carbon electrode for the determination of 2,6-diaminotoluene (TDA)

Abstract

The objective of this study was to improve the overall performance of a glassy carbon electrode (GCE) for the detection of 2,6-diaminotoluene (TDA), a possibly carcinogenic primary aromatic amines (PAAs) that poses a serious risk for the consumer' health because they can transfer from multilayer food packages including adhesives based on aromatic polyurethane (PU) systems, to the food. The modification of the electrode surface was made by means of multi-walled carbon nanotubes (MWCNTs) and mesopomus carbon nanoparticles (MCNs). The MWCNTs-MCNs/GCE allowed achieving the best performance in terms of sensitivity, as revealed by cyclic voltammetry - CV, with an oxidation peak of 20.95 mu A over 0.079 mu A of the bare GCE. The pH of the medium influenced the oxidation of 2,6-TDA, with highest sensitivity at pH similar to 7. Amperometry experiments led to an estimated detection limit of 0.129 mu M, and three linear ranges were obtained for 2,6-TDA: 0.53-11.37 mu M, 11.37-229.36 mu M, and 229.36-2326.60 mu M. Chronoamperometry experiments combined with Cottrell's theory allowed estimating a diffusion coefficient of 2,6-TDA of 1.34 x 10(-4) cm(2) s(-1). The number of electrons (n similar to 1) involved in the catalytic oxidation of 2,6-TDA was determined according to the Lavimn's theory. Real sample tests demonstrated that the modification of the sensor using nanoparticls allowed to obtain a highly sensitive and selective sensor, which can possibly used as an alternative analytical device for the rapid, easy, and reliable determination of 2,6-TDA.