Fabrication of a novel electrochemical biosensor based on easy and efficient modifications of a glassy carbon electrode for sensitive and selective determination of morphine

In this study, a selective and sensitive electrochemical determination of morphine at low concentration was carried out using electropolymerization of 3-methyl-1-phenyl-pyrazole-5-one (MPP) at the surface of a glassy carbon electrode (GCE) which was further modified by electrodeposition of cobalt nanoparticles (Co NPs) onto its surface. The electrochemical studies of morphine were performed using cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. Modification of the electrode surface increased its response to morphine which yielded a relatively wide linear range (2 to 100 μM) and a low limit of detection of 0.12 μM. The analytical characteristics of the sensor towards determination of the morphine were investigated which confirmed a good analytical performance for the sensor. Finally, the sensor was used for monitoring morphine in serum and urine samples as real matrices whose performance was both acceptable and admirable which motivated us to introduce it as a reliable method for determination of morphine in biological fluids.