Electrochemical Study and Sensing of Isoniazid in Pharmaceutical with Modified Carbon Paste Electrode with Nanoceria Particles as an Effective Catalytic Amplifier

A new electrochemical probe for detecting Isoniazid is proposed based on nanocomposite electrode modified with nanoceria particles (CeO2 NPs) as a catalytic amplifier. The main reason for the catalytic activity of CeO2 NPs attributed to their reversible dual oxidation states Ce(III)/Ce(IV) in that CeO2 NPs. Nanoceria nanoparticles have the ability to change redox states and surface properties when being in contact with electroactive compounds. Therefore, valence and defect structure of CeO2 NPs play a mainly role in this electrocatalytic reaction. Electrode surface area (A), electron transfer coefficient (α), and heterogeneous catalytic rate constant (Kh) were estimated by electrochemical techniques. The peak current is found to depend linearly on isoniazid concentration within the ranges of 5.0-140.0 μmol L–1. The limit of detection (LOD) for isoniazid is found to be 0.51 μmol L–1. Finally, the modified electrode receives many advantages such as notable catalytic activity, and acceptable reproducibility, the proposed method was used for determining isoniazid in urine and tablet samples successfully.