Multi-walled carbon nanotube modified glassy carbon electrode as a voltammetric nanosensor for the sensitive determination of anti-viral drug valganciclovir in pharmaceuticals

Valganciclovir hydrochloride (VAL) is an antiviral drug active compound which is used for the treatment of the cytomegalovirus infections. The voltammetric oxidation of VAL was investigated at multi-walled carbon nanotubes modified glassy carbon electrode using cyclic and differential pulse voltammetry over a wide pH range. The results revealed that the oxidation of VAL is an irreversible pH-dependent process in an adsorption-controlled mechanism. The results show that the oxidation signal was remarkably enhanced to provide down to the ultra trace levels. Operational parameters have been optimized. The calibration curve was linear in the concentration range of 7.50 x 10(-9)-1.00 x 10(-6) M with the detection limit of 1.52 x 10(-9) M. The reproducibility of the peak current was found 2.07% (n =5) relative standard deviation (RSD) value in pH 4.0 Britton-Robinson (BR) buffer for the modified electrode. The modified electrode showed good stability and reproducibility, and also it was successfully applied to the sensitive and selective determination of VAL in its dosage forms. (c) 2012 Elsevier B.V. All rights reserved.