Simultaneous Voltammetric Determination of Morphine and Tramadol Using Zirconium-Based Metal Organic Framework Modified Electrode

In this work, a practical approach was utilized to fabricate a zirconium (Zr)-based metal organic framework (UiO-66 MOF) via a one-pot solvothermal method, with the intention of employing it as an electrocatalyst. The characterization of UiO-66 MOF was investigated by several techniques. The synthesized UiO-66 MOF was employed to modify a screen-printed graphite electrode (UiO-66 MOF/SPGE) using a drop-casting technique. The electrochemical characteristics of the UiO-66 MOF/SPGE sensor for morphine oxidation were analyzed through various techniques, including cyclic voltammetry (CV), chronoamperometry, and differential pulse voltammetry (DPV). Under the optimized conditions, the prepared UiO-66 MOF/SPGE exhibited a linear range of 0.03 to 440.0 µM for morphine detection, as evidenced by the DPV results. The limit of detection for morphine was found to be 0.01 µM. The proposed sensor displayed excellent electro-catalytic activity toward the simultaneous determination of tramadol and morphine. The peak-to-peak potential separations between tramadol and morphine are 400 mV. Furthermore, the developed sensor was effectively utilized for the quantification of tramadol and morphine in real samples, yielding satisfactory recovery values.