Bimetallic (Zr/Ce)-UiO-66-NH₂ modified electrode for enhanced electrochemical sensing of acetaminophen

The widespread use of acetaminophen (AP) has resulted in its frequent presence in pharmaceutical waste, posing ecological and health risks. To address this, a voltametric sensor based on a bimetallic UiO-66-NH₂ metal-organic framework incorporating Zirconium (Zr) and Cerium (Ce) was developed for sensitive AP detection. The incorporation of Ce³⁺ not only introduced redox active sites but also reduced the particle size from 495-650 nm in (Zr)UiO-66-NH₂ to 230-365 nm in (Zr/Ce)UiO-66-NH₂, increasing surface area and enhancing electrocatalytic activity. The combined synergistic effect of Zr and Ce significantly improved charge transfer and enhanced oxidation current response compared to the unmodified GCE. The sensor exhibited excellent electrocatalytic performance with a wide linear range (0.072-680 μM), high sensitivity (0.496 μAμM^-1cm^-2), and a low limit of detection (0.024 μM). In addition, the sensor exhibited excellent selectivity against interfering species and maintained stable performance over 21 days. The sensor's practical applicability was validated by testing real environmental samples, achieving recovery rates of 97-103 %, and the results were consistent with those obtained using high-performance liquid chromatography (HPLC).