Electrooxidation of antihistamine drug methdilazine and its analysis in human urine and blood samples

Design of a Sensitive and Selective Voltammetric Sensor Based on a Cationic Surfactant-Modified Carbon Paste Electrode for the Determination of Alloxan

Alloxan (AL) is a toxic glucose analogue that acts as a potent diabetogenic inducer by selectively destroying the insulin-producing β-cells of the pancreas. Hence, a sensitive and selective cetyl trimethylammonium bromide (CTAB)-immobilized carbon paste electrode was utilized for the analysis of AL in the existence of anthrone. The CTAB-modified carbon paste electrode in contrast with the bare carbon paste electrode showed a magnificent behavior for the electrocatalytic oxidation of AL by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. CV studies reveal a quasi-reversible diffusion-controlled process in the potential window of -0.5 to 0.4 V at an optimum pH of 6.5 in 0.2 M phosphate buffer solution. The electrode materials were characterized by CV, field emission-scanning electron microscopy, and electrochemical impedance spectroscopy. Under optimized experimental conditions, low detection limits of 1.09 and 3.64 μM were obtained in a linear dynamic range of 5-80 μM and from 8 to 90 μM by DPV and CV methods, respectively. The performance of the modified electrode is impressive in terms of least charge transfer resistance (R ct), surface concentration (Γ), and heterogeneous electron transfer rate constant (k 0). A 50-fold excess concentration of other potential interferants such as food additives and other organic species present in the human body does not significantly alter the peak potential and peak current of AL. The analytical application of the modified sensor was appraised by determining AL in the spiked refined flour sample. The modified sensor with a swift fabrication procedure exhibited enduring stability, adequate reproducibility, and acceptable repeatability.