▎ 摘　　要

We describe a fluorescent dopamine assay that is based on the inner filter effect (IFE) of gold nano particles (AuNPs) on the fluorescence of graphene quantum dots (GQDs). The green fluorescence of GQDs is remarkably inhibited in the presence of citrate-stabilized AuNPs via IFE. Upon the addition of dopamine (DA), aggregation of the AuNPs occurs which is associated with a color change from red to blue. The IFE can no longer occur and the fluorescence of GQDs is recovered. Under the optimum conditions, a linear correlation exists between fluorescence intensity and the concentration of DA in the range from 20 nM to 200 nM with a detection limit of 15 nM (at 3 sigma/s). The assay is rapid, inexpensive and highly sensitive. (C) 2016 Elsevier B.V. All rights reserved.