Graphene quantum dots and carbon nano dots for the FRET based detection of heavy metal ions

摘要： We demonstrate the development of a FRET based novel optical sensing system for the efficient detection of heavy metal pollutants. The studied sensing system is comprised of graphene quantum dots (GQDs) as donor and carbon nano dots (C-Dots) as an acceptor component. When these fluorescent nano-dots are within the FRET distance, fluorescence of the donor GQDs is quenched by the non-radiative energy transfer to acceptor C-Dots. Fluorescence lifetime is measured by time resolved photo-luminescence spectroscopic study to validate the FRET efficacy of the mix dot based sensor system. Upon gradual addition of heavy metals like arsenic (As5+) and mercury (Hg2+) into this sensor system, a significant amount of reduction in the investigated FRET signal is experienced. The detailed mechanisms of the molecular interactions between GQDs and C-Dots are thoroughly studied by UV–Visible absorption, infrared, steady state and time resolved spectroscopy.