An ultrasensitive and selective voltammetric sensor with an ultratrace-level detection limit is introduced for ketoconazole (KTC) determination in real samples using a modified carbon paste electrode with a sheaf-like Ce-BTC MOF nanostructure and ionic liquid. The as-synthesized nanostructure was characterized by several techniques, including energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The electrocatalytic performance of the developed electrode was observed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), and chronoamperometry. The limit of detection (LOD) of the developed sensor for KTC is 0.04 μM, and the response was found to be in the dynamic concentration range of 0.1-110.0 μM in a phosphate buffer solution. The proposed electrode exhibits acceptable electrocatalytic activity for KTC oxidation with a high sensitivity of 0.1342 μA·μM-1. The ability of the fabricated sensor to monitor KTC in real aqueous samples is demonstrated using standard addition data.
Keywords: chemically modified sensors; electrochemical detection; nanostructure ketoconazole sensing; sheaf-like Ce-BTC MOF.