Turn off detection of Mercury ions with the use of sensitive and selective fluorescence graphene quantum dot

A facile method for the highly sensitive and selective sensing of Hg2+ based on graphene quantum dots (GQDs) has been developed. An easy, blue, one-pot synthesis of graphene quantum dots was established by thermal pyrolysis of citric acid with homogenous size distribution. GQDs provide a fluorescent emission of 450 nm after excitation at 365 nm. The fluorescent emission of the GQDs was quenched in the presence of Hg2+. This occurred because of their absorption on GQDs’ surface by means of electrostatic interactions and electron transfer. The sensor is highly sensitive, and showed a response to Hg2+ within a wide concentration range of 0.1-200 µM with 50nM limits of detection.

کلیدواژه ها:

graphene quantum dot ، mercury ions ، fluorescence ، sensor ، pyrolysis