A sensitive electrochemical sensor for rapid and selective determination of venlafaxine in biological fluids using carbon paste electrode modified with molecularly imprinted polymer-coated magnetite nanoparticles

Novel molecularly imprinted polymer-coated magnetite nanoparticles (VENMNPs) for the determination of venlafaxine (VEN) were introduced. The synthesized nanoparticles were used as a nano-modifier for carbon paste electrode. The modified electrode was used as an electrochemical sensor for electro-oxidation of venlafaxine, and subsequently for the drug sensitive and selective determination. Electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry were employed to characterize the modified carbon paste electrode. Various experimental parameters, that can potentially affect the electrochemical signal of the electro-oxidation of VEN, including pH, VENMNPs dosage, stirring time, accumulation potential and time, were optimized. The results showed that under the optimum condition, sensitive determination of venlafaxine in concentration range 0.01–10.0 μmol L−1 is achievable. The detection limit for the drug determination was obtained as 6.0 nmol L−1. Finally, the results of the drug concentration analysis in human urine and blood serum samples showed that a powerful alternative method for VEN determination in biological fluids is developed.