A new electrochemical sensor for determination of fentanyl lethal drug by screen-printed carbon electrode modified with open-ended channels of Zn (II)-MOF

Fentanyl is a potent, effective analgesic and narcotic drug widely used for anesthesia and chronic pain control. In this study, a simple electrochemical method for the determination of fentanyl in aqueous solutions was developed. Modification of the screen-printed carbon electrode (SPCE) was performed by casting a metal-organic framework (MOF) on its surface. Characterization of the zinc-based MOF (Zn(II)-MOF) modifier was investigated by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier ‎transform infrared (FT-IR) and X-ray diffraction (XRD) techniques. Differential pulse voltammetry (DPV) technique was used for evaluating the fentanyl electrochemical behavior on the electrodes. The optimum experimental conditions were investigated by examining the effect of the scan rate and pH on the cyclic voltammetry (CV) and DPV responses, respectively. The results showed that fentanyl has an irreversible behavior at the potential of 0.9 V that its current increases in the presence of MOF. The application of the presented electrode with the DPV method showed a detection limit of 0.3 μM in the concentration range of 1-100 μM (linear range) for the fentanyl in the aqueous solution. The modified electrode was successfully used to determine low levels of fentanyl in urine and plasma as the real samples.