Characterization of a highly Cu2+-selective fluorescent probe derived from rhodamine B

A rhodamine B derivative was synthesized and characterized as a highly selective and sensitive probe for Cu2+ in ethanol-water solution (2:3, v:v, pH7.4, 50 mM HEPES). A prominent fluorescence enhancement at 575 nm was observed in the presence of Cu2+, accompanied by the change in the absorption spectrum. Under the optimal conditions, a good linear range of 0.5-1.5 mu M with a detection limit of 1.6 x 10(-7) M were obtained. Furthermore, confocal laser scanning microscopy experiments have proven that this probe is cell-permeable and can respond to changes in intracellular Cu2+ in living cells. (C) 2012 Elsevier Ltd. All rights reserved.