Simultaneous and selective determination of dopamine and tyrosine in the presence of uric acid with 2D-MoS₂ nanosheets modified screen-printed carbon electrodes

Two-dimensional molybdenum disulphide nanosheets (2D-MoS2) were prepared by liquid-phase exfoliation and used to modify screen-printed carbon electrodes (SPCE), in order to develop an electrochemical sensor for the simultaneous determination of dopamine (DA) and tyrosine (Tyr) in presence of uric acid (UA). To demonstrate the layered morphology, the synthesized molybdenum disulphide nanostructures, have been characterized by Raman and SEM in both liquid dispersion and after deposition on SPCE. The performances of the 2D-MoS2-SPCE electrode have been tested and optimized in terms of sensitivity, reaching high sensitivity values of 1044 mu A mM(-1) cm(-2) for DA and 321 mu A mM(-1) cm(-2) for Tyr, selectivity against UA and high stability. The simultaneous detection of these biomolecules is the first study so far reported with the use of 2D-MoS2-based sensors. The promising characteristics of the developed electrodes suggest 2D-MoS2 as a versatile, low cost and easy to produce material for the next generation of electrochemical sensors of a variety of important biomolecules.