Cerium(IV) and Iron(III) Oxides Nanoparticles Based Voltammetric Sensor for the Sensitive and Selective Determination of Lipoic Acid

• Published in: Sensors (Basel, Switzerland) Vol. 21; no. 22; p. 7639
• Main Authors: Ziyatdinova, Guzel, Gimadutdinova, Liliya
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 17.11.2021; MDPI
• Subjects: amperometric sensors; Anodizing; Ascorbic acid; Carbohydrates; Carbon; Cerium; Electrochemical Techniques; Electrodes; Electron transfer; electrooxidation; Ethanol; Ferric oxide; Glassy carbon; Iron; Limit of Detection; Lipoic acid; metal oxide nanoparticles; Metal oxides; Nanomaterials; Nanoparticles; Oxidation; Oxides; pharmaceutical analysis; Sensors; Software; Spectrum analysis; Standard deviation; Thioctic Acid; Voltammetry; Netherlands; United States > US; Germany; Russia; metal oxide nanoparticles; lipoic acid; electrooxidation; amperometric sensors; pharmaceutical analysis
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s21227639

A novel voltammetric sensor based on CeO ·Fe O nanoparticles (NPs) has been developed for the determination of lipoic acid, playing an essential role in aerobic metabolism in the living organism. Sensor surface modification provides a 5.6-fold increase of the lipoic acid oxidation currents and a 20 mV anodic shift of the oxidation potential. The best voltammetric parameters have been obtained for the 0.5 mg mL dispersion of CeO ·Fe O NPs. Scanning electron microscopy (SEM) confirms the presence of spherical NPs of 25-60 nm, and their aggregates evenly distributed on the electrode surface and formed porous coverage. This leads to the 4.4-fold increase of the effective surface area vs. bare glassy carbon electrode (GCE). The sensor shows a significantly higher electron transfer rate. Electrooxidation of lipoic acid on CeO ·Fe O NPs modified GCE is an irreversible diffusion-controlled pH-independent process occurring with the participation of two electrons. The sensor gives a linear response to lipoic acid in the ranges of 0.075-7.5 and 7.5-100 μM with the detection limit of 0.053 μM. The sensor is selective towards lipoic acid in the presence of inorganic ions, ascorbic acid, saccharides, and other S-containing compounds. The sensor developed has been tested on the pharmaceutical dosage forms of lipoic acid.