Ti 3 C 2 T x Coated with TiO 2 Nanosheets for the Simultaneous Detection of Ascorbic Acid, Dopamine and Uric Acid.

Two-dimensional MXenes have become an important material for electrochemical sensing of biomolecules due to their excellent electric properties, large surface area and hydrophilicity. However, the simultaneous detection of multiple biomolecules using MXene-based electrodes is still a challenge. Here, a simple solvothermal process was used to synthesis the Ti 3 C 2 T x coated with TiO 2 nanosheets (Ti 3 C 2 T x @TiO 2 NSs). The surface modification of TiO 2 NSs on Ti 3 C 2 T x can effectively reduce the self-accumulation of Ti 3 C 2 T x and improve stability. Glassy carbon electrode was modified by Ti 3 C 2 T x @TiO 2 NSs (Ti 3 C 2 T x @TiO 2 NSs/GCE) and was able simultaneously to detect dopamine (DA), ascorbic acid (AA) and uric acid (UA). Under concentrations ranging from 200 to 1000 μM, 40 to 300 μM and 50 to 400 μM, the limit of detection (LOD) is 2.91 μM, 0.19 μM and 0.25 μM for AA, DA and UA, respectively. Furthermore, Ti 3 C 2 T x @TiO 2 NSs/GCE demonstrated remarkable stability and reliable reproducibility for the detection of AA/DA/UA.