A 2-(2′-hydroxyphenyl)quinazolin-4(3H)-one derived fluorescence ‘turn on’ probe for recognition of Hg^sup 2+^ in water solution and its live cell imaging

A new fluorescence "turn on" Hg2+ probe 3,3'-(((2-hydroxy-5-methyl-3-(4-oxo-3,4-dihydroquinazolin-2-yl)phenyl)methylene)bis(sulfanediyl))dipropionic acid (QBDA) based on Hg2+-triggered transformation of dithioacetal to aldehyde has been developed. Probe QBDA exhibits high selectivity and sensitivity to Hg2+ over other metal ions in PBS buffered (20 mM, pH = 7.4) solution, the detection limit of QBDA for Hg2+ was estimated to be 2.04 × 10-8 M and the potential interference from Ag+ can be suppressed in PBS buffered normal saline solution. Living cell imaging investigations show that QBDA possesses good cell permeability, and can act as a light-up imaging probe for Hg2+ ions in MCF-7 cell.