Recognition of copper and hydrogen sulfide in vitro using a fluorescein derivative indicator

We report the development of a fluorescein-based chemosensor (L1) for monitoring ions or micromolecules (H(2)S). Copper ions are known to be toxic at high concentrations and hydrogen sulfide induces various problems. Herein we develop a simple method for detecting Cu(II) and H(2)S with high selectivity and sensitivity. The chemosensor L1 displays on-off-on type fluorescence change with alternately added Cu(II) and H(2)S to the media along with reversible forming-separating of the complex. The potential biomedical relevance of the chemical mechanisms involved in the detection of L1 is described.