Electrochemical Sensing of Thioridazine in Human Serum Samples Using Modified Glassy Carbon Electrode

In this work, thioridazine (TR) as an important neuroleptic drug has been detected simply by an electrochemical approach using a glassy carbon electrode modified by nickel oxide nanoparticles decorated graphene quantum dot (NiO/GQD/GCE). The bare and modified electrodes were characterized using the scanning electron microscope (SEM) and electrochemical techniques. The cyclic voltammetric studies demonstrated that the NiO/GQD/GCE has remarkably enhanced electro-catalytic activity towards the oxidation of TR in neutral solutions. The results (significant increase in peak current and a negative shift in TR oxidation potential) are related to the increase in electrode surface area and electron transfer rate along with the modifier catalytic role. The NiO/GQD modified electrode used for sensitive determination of TR by differential pulse voltammetry (DPV) method. The effect of experimental parameters on the obtained results was studied and optimized. The NiO/GQD/GCE modified electrode revealed a linear response in the concentration range from 2×10^-9 to 200×10^-9 M with a limit of detection (LOD) equal to 0.05×10^-9 M (S/N=3). The sensor was applied to determine TR in serum and pharmaceutical samples, which proves this sensor is an ideal device for TR determination.