Electrochemical sensor for isoniazid detection by using a WS2/CNTs nanocomposite

This paper presents a new modified electrode that combines the high electrical conductivity of carbon nanotubes (CNTs) with the catalytic sites of WS₂ (named WS₂/CNTs) for isoniazid detection. Electrochemical and electroanalytical properties of the WS₂/CNTs/glassy carbon electrode (GCE)-modified electrodes were investigated by cyclic voltammetry and differential pulse voltammetry (DPV). The composite material was characterized by Raman spectroscopy, X-ray diffractometry (XRD), and scanning electron microscopy . The electrochemical performance of the WS₂/CNTs/GCE sensor exhibited a limit of detection of 0.24 μM with a linear range from 10 to 80 μM of isoniazid using DPV. This sensor provided enhanced stability and electrocatalytic activity for isoniazid oxidation reactions. Recoveries ranging from 96.9 to 104.5% were calculated, demonstrating satisfactory accuracy of the proposed method. The improvement of electrochemical activity was assigned to synergic effects obtained by combining the catalytic sites from WS₂ and the known electrical conductivity and large surface area of the CNTs, resulting in an anticipation of the oxidation peak of isoniazid in about 400 mV in comparison with bare GCE.