化学法制备水溶性良好的石墨烯及其荧光淬灭应用

摘要

Water-soluble graphene has been synthesized by two-step reduction of graphene oxide.To improve the solubility of graphene in water,a diazonium salt reaction for sulfonating the graphene was introduced between the two steps.Morphology,composition and structure of the as-grown graphene were characterized by atomic force microscopy (AFM),UV-vis spectroscopy,Raman scattering and X-ray photoelectron spectroscopy (XPS).Bilayer gaphene sheets with lateral size of ～1 μm were obtained and can be well dispersed in water.Oxygen-containing functional groups bound to the graphene plane were significantly removed after the reduction processes.Fluorescence quenching effect of graphene on Rhodamine B molecules was demonstrated,which indicates that graphene is an effective fluorescence quencher.Graphene is promising in fluorescence detecting and bio-sensing.%采用两步还原法对氧化石墨烯(GO)进行还原,并在还原过程中通过重氮盐反应对石墨烯表面进行磺酸化,改善了石墨烯在水中的溶解性.采用原子力显微镜(AFM)、紫外-可见吸收光谱(UV-vis)、拉曼光谱(Raman)和X射线光电子能谱(XPS)等手段对石墨烯的形貌以及在还原过程中的组成结构变化进行了表征.经过还原和磺酸化的石墨烯,碳原子平面上的含氧官能团大量消失,得到的石墨烯片尺寸约为1μm,层数大致为双层,可以均匀稳定地分散在水中.在此基础上,研究了石墨烯作为荧光淬灭底物淬灭高量子效率的荧光染料罗丹明B溶液的行为,证实了石墨烯是一种良好的荧光淬灭剂.这为其在荧光探测和生物分子传感方面的应用打下了基础.