基于功能化纳米金和石墨烯量子点的比色/荧光双信号检测Pb2+研究

A sensitive dual-signaling probes for lead ions detection based on inner filter effect of functionalizing gold nanoparticles on the fluorescence of graphene quantum dots

以石墨烯量子点(GQDs)为荧光探针,金纳米粒子(Au NPs)为比色探针,构建一种简单、绿色、灵敏的Pb^2+荧光和比色双信号检测方法.比色分析基于Pb^2+诱导Au NPs聚集引起的颜色变化;荧光分析则基于二硫代氨基甲酸盐功能化金纳米粒子(DTC-Au NPs)对石墨烯量子点(GQDs)的内滤光效应(IFE),在Pb^2+存在的情况下,由于Pb^2+诱导DTC-Au NPs聚集,Au NPs对GQDs的内滤作用明显下降,GQDs的荧光恢复,该方法对Pb^2+的检测限为0.35μmol/L,可用于实际水样中Pb^2+的可视化现场检测.

With graphene quantum dots(GQDs)as fluorescent probe and gold nanoparticles(Au NPs)as colorimetric probe,a simple,green,sensitive dual-signaling(fluorometric and colorimetric)detection method for Pb^2+was constructed.The colorimetric analysis were based on the colour transformation of Pb^2+-induced gold nanoparticles aggregation.The fluorescent assay were based on the inner filter effect(IFE)of dithiocarbamate functionalized gold nanoparticles(DTC-Au NPs)on the fluorescence of GQDs.The fluorescence of GQDs was significantly quenched via the IFE of Au NPs when DTC-Au NPs was added into it.With the presence of Pb^2+,IFE-decreased emission of GQDs could be recovered.Because Pb^2+could induce the aggregation and corresponding absorbance decreased of Au NPs.The detection limit for Pb^2+was 0.35μmol/L.Upon adding Pb^2+,the wine red DTC-Au NPs suspension changed to purple and then to black blue.These colorimetric techniques could be used for the detection of Pb^2+with comparatively high sensitivity.Therefore,the present assay was promising for on-site screening of Pb^2+in water.