Preparation And Electrochemical Properties Of MoS₂ Nanoflowers-Graphene Composite

Nanostructured MoS₂ nanoflowers（MoS₂ NFs）exhibits good electrocatalytical properties and more active sites,however,some defects restrains the further development in the area of electrochemical biosensors,such like low conductivity.With the excellent biocompatibility,large specific surface area,good chemical stability and high catalytic efficiency,the graphene has been widely studied as a biosensor material.The hybridization of graphene could improve the conductivity of composite effectively and the synergetic effect between the graphene and MoS₂ NFs makes the composite show outstanding electrochemical performance.Herein,the graphene oxide（GO）prepared by Hummers method was dispersed into suspension with the assistance of ultrasound,then the MoS₂ NFs synthesized by hydrothermal method was put into the suspension,next the mixed solution was spray coated onto the surface of indium tin oxide（ITO）coated glass,finally the MoS₂ NFs-graphene composite modified ITO electrode（MoS₂ NFs-Gr/ITO）was fabricated after the heat-treatment.The scanning electron microscopy（SEM）,X-ray diffraction（XRD）and Raman spectroscopy were employed to characterize the morphology and structure of MoS₂NFs-Gr composite.The SEM image show that MoS₂ NFs are composed by nanosheets and the diameter is about 1μm.The graphene coated on the surface of MoS₂ NFs is so transparent that it could be identified the structure of nanoflower.XRD analysis show that the composite is composed of MoS₂ NFs and graphene.Raman indicate that the graphene is few-layered.The cycle voltammetry（CV）was used to investigate the reaction mechanism and reversibility of MoS₂ NFs-Gr/ITO electrode and the differential pulse voltammetry（DPV）was used to detect the sensitivity and limit of detection.The result show that in the concentration range of 5-60μM,the sensitivity of prepared electrode is 2.29μA·μM^-1 for dopamine（DA）and 1.88μA·μM^-1 for uric acid（UA）and the limit of detection is 0.12μM for DA and 0.14μM for UA,respectively.The electrode also shows good selectivity,anti-interference,reproducibility and stability.And it is can be used for detecting real biomolecules.