A sensitive fluorescent probe for Cu2+ based on rhodamine B derivatives and its application to drinking water examination and living cells imaging

A new rhodamine derivative (RhS) with a recognition capability for Cu2+ was synthesized and employed as a reversible fluorescent probe for Cu2+ in drinking water and living cells. The spirolactam ring-opening of probe RhS induced by Cu2+ lead to a highly selective fluorescence turn-on response toward Cu2+ over other metal ions with micromolar sensitivity. The 1:1 stoichiometric structure between RhS and Cu2+ were supported by Job's plot, MS and DFT theoretical calculations. The analytical results obtained by UV-vis and fluorescence spectrophotometry show that the linear range and the limit of detection (LOD) of the present probe for Cu2+ are 0.50-20.00 and 0.11 mu mol L-1, respectively. The present probe was applied to the detection of Cu2+ in drinking water with the recoveries ranging from 100.4 to 101.2%, and the fluorescence imaging for living HeLa cells. (C) 2015 Elsevier B.V. All rights reserved.