Sensitive Electrochemical Determination of Morphine Using Gold Nanoparticles–Ferrocene Modified Carbon Paste Electrode

An effective electrochemical sensor based on carbon paste (CP) electrode with ferrocene /gold nanoparticles GNFMCPE, is introduced for selective determination of morphine (MO) in presence of interference compounds as ascorbic acid (AA) and uric acid (UA). Furthermore, the modified electrode is used for simultaneous determination in presence of dopamine (DA) or l-norepinephrine (NEP) in 0.04 mol L−1 universal buffer solution (B-R) (pH 7.4), a well defined oxidation peaks with high current response and good potential peak separation is obtained compared to the unmodified electrode. The electrochemistry of MO is investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance measurements (EIS). The morphine concentration could be measured in the concentration range of 1.0×10−6 to 18.0×10−4 mol L−1 with a detection limit of 3.507 × 10−9 mol L−1 and a correlation coefficient of 0.9994. The sensor has also been successfully applied to the determination of morphine spiked into diluted urine samples with a low detection limit and satisfied recovery. The good results indicate that GNFMCPE holds great promise in practical application.