Application of a UiO-67 metal-organic framework for the sensitive electrochemical detection of omeprazole in the biological samples

A novel electrochemical sensor based on a UiO-67 metal-organic framework (MOF) modified with a carbon paste electrode (UiO-67/CPE) was developed for the sensitive and selective quantification of omeprazole (OM). The UiO-67/CPE exhibited remarkable electrocatalytic activity toward OM oxidation vs. bare CPE. Also, the improved electrochemical behavior can be ascribed to the remarkable textural properties of UiO-67, namely its high surface area and porous architecture. Experimental conditions, including UiO-67 amount in the UiO-67/CPE and pH of buffer solution were optimized through a one variable at a time. The results indicated that the optimal conditions were at 0.03 g of UiO-67 and a pH of 3.0. The resulting UiO-67/CPE sensor offered a broad linear response (0.15–224.83 µM), a low detection limit of 0.15 µM and excellent precision (RSD = 3.83 % for reproducibility and 3.27 % for repeatability). The UiO-67/CPE sensor enabled sensitive determination of OM concentrations in human plasma samples, with results confirming its high reliability through excellent recoveries (98–105 %) and high selectivity against potential interferences.