MoS₂/Ti₃C₂ composite interface as an electrochemical platform for dopamine and ascorbic acid sensing

The electrochemical quantification of dopamine (DA) and ascorbic acid (AA) is of great physiological importance. However, it remains challenging due to the sluggish electrode kinetics of both molecules, motivating the design of electrode materials with tailored interfacial properties. Here, a porous layered MoS₂/Ti₃C₂ nanocomposite with in-situ grown MoS₂ on Ti₃C₂ MXene is prepared via a facile hydrothermal route and evaluated as a modified electrode material for DA and AA sensing. Electrochemical characterization reveals that the composite substantially enhances the oxidation peak current for both analytes relative to pristine MoS₂, indicating improved electrocatalytic activity. For individual detection, the composite electrode exhibits linear response ranges of 0.8-1.6 mM for DA and 0.7-3.3 mM for AA, with detection limits (S/N = 3) of 4.5 μM and 9.2 μM, respectively. The observed electrochemical performance is attributed to a synergistic mechanism: the highly conductive Ti₃C₂ framework supports rapid charge transfer, while the in-situ grown MoS₂ nanosheets form a three-dimensional porous architecture that mitigates Ti₃C₂ restacking, increases the density of accessible active sites, and promotes analyte diffusion. These findings establish the MoS₂/Ti₃C₂ nanocomposite as a promising material platform for continuing development in electrochemical biosensing, including application in decentralized diagnostics for neurological disorders.