离子液体化石墨烯量子点及其对H_(2)PO_(4)^(-)的荧光增强识别

Ionic liquid-functionalized graphene quantum dots for fluorescence enhanced recognition of H;PO

通过表面修饰法制备了离子液体化石墨烯量子点(GQDs-IL),采用透射电子显微镜(TEM)、原子力显微镜(AFM)、傅里叶变换红外光谱仪(FTIR)、X射线光电子能谱仪(XPS)等对其形貌和结构进行了表征。结果表明离子液体与GQDs通过酰胺键相连,GQDs-IL的粒径分布均匀,平均粒径为4.6 nm。光谱性能表明,GQDs-IL在二甲基甲酰胺(DMF)溶液中,在常见阴离子(F^(-),Cl^(-),Br^(-),I^(-),AcO^(-),HSO^(-),H_(2)PO_(4)^(-),CN^(-))中能够专一性地识别H_(2)PO_(4)^(-),滴加H_(2)PO_(4)^(-)后引起荧光增强3.61倍,检出限为3.2 nmol/L,其它阴离子的存在并未干扰GQDs-IL对H_(2)PO_(4)^(-)的检测。

Ionic liquid-functionalized graphene quantum dots(GQDs-IL) was prepared by surface modification method, and the morphological structure of GQDs-IL was characterized by transmission electron microscope(TEM), atomic force microscope(AFM), Fourier transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS). The results demonstrated that the ionic liquid group and GQDs were covalently linked by amide bond, and GQDs-IL had a uniform particle size with an average diameter of 4.6 nm. The spectral performance showed that GQDs-IL could specifically recognize H_(2)PO_(4)^(-)among common anions(F^(-), Cl^(-), Br^(-), I^(-), AcO^(-), HSO^(-), H_(2)PO_(4)^(-), CN^(-)) in dimethylformamide(DMF) solution. The addition of H_(2)PO_(4)^(-)led to a 3.61-fold fluorescence enhancement with a detection limits of 3.2 nmol/L. Other anions had no obvious interference for GQDs-IL to detect H_(2)PO_(4)^(-).