A Novel Electrochemical Sensing Platform for the Detection of the Antidepressant Drug, Venlafaxine, in Water and Biological Specimens

A stable bimetallic catalyst composed of Co–Pd@Al₂O₃ was synthesized using a wet impregnation method, followed by calcination and H₂ reduction. The synthesized catalyst was thoroughly characterized using XRD, BET, SEM, EDX, and TPR techniques. The catalyst was then drop-casted on a glassy carbon electrode (Co–Pd@Al₂O₃/GCE) and applied for the sensitive and selective electrochemical determination of a common antidepressant drug, venlafaxine (VEN). The proposed sensor (Co–Pd@Al₂O₃/GCE) demonstrated a remarkable catalytic activity for the electro-oxidation of VEN, with a decent repeatability and reproducibility. The pH dependent responsiveness of the electro-oxidation of VEN helped in proposing the redox mechanism. A linear relationship between the peak current and concentration of VEN was observed in the range of 1.95 nM to 0.5 µM, with LOD and LOQ of 1.86 pM and 6.20 pM, respectively. The designed sensor demonstrated an adequate selectivity and significant stability. Moreover, the sensor was found to be quite promising for determining the VEN in biological specimens.