TiO2 nanoparticles modified sensor for theophylline drug

A simple modified sensor has been proposed using titanium dioxide (TiO2) nanoparticles for the electro-analysis of theophylline (TP) in phosphate buffer solution (PBS). The surface was characterized by atomic mass spectroscopy (AFM). The electrooxidation of the drug was studied by employing techniques such cyclic voltammetry (CV) and square wave voltammetry (SWV). The heterogeneous rate constant was calculated and a suitable electrochemical oxidation mechanism was also proposed. The concentration variation of the drug showed good linear response with lower detection limit value. The influence of physicchemical parameters like scan rate, pH, accumulation time, and amount of the modifier, excipients, metal ions and concentration on the voltammetric behavior of an analyte were studied. To test its analytical applications it was applied to determine drug in pharmaceutical and urine samples with good recovery values. (C) 2019 Elsevier Ltd. All rights reserved.