Histidine based fluorescence sensor detects Hg2+ in solution, paper strips, and in cells

A chemosensor having a bipodal thiocarbamate scaffold attached to histidine moieties senses Hg(2+) with a remarkable selectivity. The binding results in a 50 nm blue shift in the fluorescence spectra and a 19-fold enhancement of the fluorescence quantum yield of the ligand. In addition to the detection of Hg(2+) visually under UV light in solution, the chemosensor was used for fabrication of paper strips that detected Hg(2+) in aqueous samples. The sensor was also used for imaging Hg(2+) in adult zebrafish and in human epithelial carcinoma HeLa S3 cells.