Electrochemical Determination of Sildenafil Using Ni/UiO‐66‐Modified Electrode

The present article utilized a voltammetric sensor based on a metal‐organic framework from the University of Oslo −66/nickel (Ni/UiO‐66) to determine sildenafil (SIL). X‐ray diffraction, scanning electron microscopy, and electrochemical techniques were employed to characterize various physicochemical properties of Ni/UiO‐66. Doping Ni into UiO‐66 does not alter the UiO‐66 framework. The prepared Ni/UiO‐66 exhibited a substantial surface area of approximately 1060.3–1200.3 m 2 ⋅g −1 . Its morphology consisted of particles measuring around 240–420 nm with well‐defined octahedral geometry. Ni/UiO‐66 demonstrated good electrocatalytic oxidation activity toward SIL oxidation, showing significant voltammetric responses, likely due to the combined effects of UiO‐66 and NiO. The electrochemical kinetics study indicated that the electrocatalytic oxidation of SIL is irreversible and involves a one proton/one electron mechanism. The oxidation peak current of SIL is linear with respect to SIL concentration in the range of 0.25–1.99 μM, with a low detection limit of 0.50 μM. Furthermore, Ni/UiO‐66 exhibited high selectivity, reproducibility, and repeatability. The proposed Ni/UiO‐66/GCE was utilized to measure SIL in human urine, yielding satisfactory recoveries.