Utility of Gold/Multiwalled Carbon Nanocomposite for Electrochemical Determination of Omarigliptin in Tablets and Human Plasma

An innovative voltammetric sensor was developed to estimate omarigliptin, a novel long-acting anti-diabetic drug. The sensor utilized a carbon paste electrode enhanced with a nanocomposite of carbon nanotubes and electrodeposited gold nanoparticles. The modified electrode was characterized using scanning electron microscopy and electrochemical impedance spectroscopy. The modification significantly improved the electrode’s sensitivity and electrochemical efficiency and decreased its electron transfer resistance. The surface area of the modified electrode increased by about 2.8-fold compared to the bare electrode. Omarigliptin’s oxidation behavior on the modified electrode was pH-dependent and irreversible, resulting in a peak current 4 times higher than the unmodified electrode. The modified electrode revealed good reproducibility, reusability, and stability. It allows for sensitive voltammetric analysis of omarigliptin over a linear range of 0.4–27 μM (LOD = 0.12 μM) and good applicability in tablets and plasma. The recovery percentages were 98.47%–101.27% in tablets and 95.86%–105.02% in plasma. The modified electrode exhibits good selectivity towards omarigliptin without interference from tablet excipients, endogenous plasma components, and co-administered drugs. The comparison with the reported methods reveals the superiority of the proposed method in terms of sensitivity, selectivity, applicability, and eco-friendliness. Finally, the proposed method demonstrates excellent environmental profiles based on recent assessment metrics.