Nano Research

Article Title

Dual-emissive nanohybrid of carbon dots and gold nanoclusters for sensitive determination of mercuric ions


Au nanoclusters, carbon nanodots, nanohybrid probe, mercury ion


The present work reports a sensitive and selective fluorescent sensor for thedetection of mercury ion, Hg(II), by hybridizing carbon nanodots (C-dots) andgold nanoclusters (Au NCs) through intrinsic interactions of the two components.The C-dots serve as the reference signal and the Au NCs as the reporter. Thismethod employs the specific high affinity metallophilic Hg2+–Au+ interactionswhich can greatly quench the red fluorescence of Au NCs, while the bluefluorescence of C-dots is stable against Hg(II), leading to distinct ratiometricfluorescence changes when exposed to Hg(II). A limit of detection of 28 nM forHg(II) in aqueous solution was estimated. Thus we applied the sensor for thedetection of Hg(II) in real water samples including tap water, lake water andmineral water samples with good results. We further demonstrated that a visualchemical sensor could be manufactured by immobilizing the nanohybrid probeon a cellulose acetate circular filter paper. The paper-based sensor immediatelyshowed a distinct fluorescence color evolution from pink to blue after exposureto a drop of the Hg(II) solution.

Graphical Abstract


Tsinghua University Press