A MXene/MoS2 heterostructure based biosensor for accurate sweat ascorbic acid detection

Biosensors with high sensitivity to sweat composition analysis are essential for non-invasive, real-time physio-logical monitoring of individual health status. However, it is challenging to construct a well-conductive and stable interface for electrochemical sensors. Here, we construct a sensitive sweat biosensor for ascorbic acid (AA) quantification built on a heterostructure with three-dimensional (3D) linked network microstructures made from two-dimensional (2D) MoS2 nanosheets and 2D Ti3C2 MXene. The as obtained 2D/2D heterostructures presented numerous active sites and avoid the issue of reduced surface areas, which was generally brought on by the accumulation of 2D nanomaterials. The electrode modified with 2D/2D heterostructure could realize efficient electron transport by abundant accesses to absorb AA molecules. Based on the inherent conductivity, extremely porous structure, and active catalytic properties of 2D/2D heterostructures, the biosensor for detecting the AA in artificial sweat had a sensitivity of 54.6nA mu M-1 and a detection limit of 4.2 mu M. This study provided a new promising approach for the design of high-performance sensing interfaces and facilitated the widespread use of personalized diagnostic devices.