TiO2/Graphene/Chitosan-Nanocomposite-Based Electrochemical Sensor for the Sensing of Anti-HIV Drug Topotecan

A highly sensitive and stable TiO2/graphene/chitosan (TiO2/GRP/CHIT) modified glassy carbon electrode was developed. The sensor exhibits excellent electrocatalytic activity with fast response and convenient determination of an anti-HIV drug Topotecan (TPT). Moreover, from the response characteristics of cyclic voltammetry(CV) and square wave voltammetry (SWV), it was observed that TPT could be effectively accumulated at TiO2/GRP/CHIT/GCE and resulted in a sensitive anodic peak current in Britton-Robinson buffer (pH 5.6). Under the optimized experimental conditions, electro-oxidation of TPT demonstrates linearity within a dynamic concentration of 100 to 1200 ng/mL, with a detection limit of 122.07 ng/mL (LOD) and a quantification limit of 369.9 ng/mL (LOQ). On the basis of the electrochemical measurements, electrode dynamics parameters have been evaluated and the sensor has been successfully employed for determination of TPT in pharmaceutical formulation.