High-quality molybdenum disulfide nanosheets with 3D structure for electrochemical sensing

An electrochemical sensor has been developed for simultaneous detection of dopamine (DA), uric acid (UA) and ascorbic acid (AA) based on pure MoS2 nanosheets modified electrode. The MoS2 nanosheets are achieved via a facile strategy, one-step pyrolysis of ammonium molybdate, thiourea and layered g-C3N4 template. Possessing hierarchical porous structure and large pore volume as well as good conductivity, MoS2 nanosheets demonstrates significantly improved electrocatalytic activity toward oxidation of AA, DA, and UA. In the coexisting system, the peak separation of AA-DA, DA-UA and AA-UA is 208.3 mV, 128.0 mV and 336.3 mV, respectively, which is much larger than for other MoS2-based catalyst. On the basis of large potential separation and high current response, selective and sensitive simultaneous determination of AA, DA, and UA was successfully accomplished by DPV, displaying a linear response from 5 to 1200 M, from 1 to 900 M, and from 1 to 60 M with a detection limit (S/N = 3) of 0.82, 0.15, and 0.06 M. This work highlights the importance of Mo-edge sites of MoS2 and hierarchical porous structure for efficient catalysis. (C) 2016 Elsevier B.V. All rights reserved.