A hierarchical 3D camellia-like molybdenum tungsten disulfide architectures for the determination of morphine and tramadol.

A practical technique was applied to fabricate MoWS2 nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. The characterization of MoWS2 nanocomposite was investigated by several techniques to identify the size, crystal structure, and elemental composition. MoWS2 nanocomposite exhibited a unique and well-defined hierarchical structure with neatly and densely piled nanopetals acting as the active sites in the electrocatalytic reactions. A carbon screen-printed electrode (CSPE) modified with interesting MoWS2 nanopetals (MoWS2/CSPE) was constructed. Subsequently, the electrochemical oxidation of morphine on fabricated MoWS2/CSPE was studied. Experimental results confirm that under optimized conditions, the maximum oxidation current of morphine occurs at 275 mV in the case of MoWS2/CSPE that is around 100 mV more negative than that observed in the case of the unmodified CSPE and about 2.6 times increase was observed for the oxidation peak current. The analytical approach was obtained by differential pulse voltammetry in accordance with the relationship between the oxidation peak current and the morphine concentration. The oxidation peak currents for morphine were found to vary linearly with its concentrations in the range of 4.8 × 10-8-5.05 × 10-4 M with the detection limit of 1.44 × 10-8 M. Two completely separated signals occured at the potentials of 275 mV and 920 mV for oxidation of morphine and tramadol at the surface of MoWS2/CSPE which are sufficient for determination of morphine in the presence of tramadol. The presence of morphine was also detected in real samples using the introduced approach. Graphical abstract Schematic representation of fabrication of the MoWS2 nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. A carbon screen-printed electrode was modified with MoWS2 nanocomposite. Subsequently, the electrochemical oxidation of morphine on the fabricated electrode was studied.