Highly sensitive dansyl-based chemosensor for detection of Cu2+ in aqueous solution and zebrafish

Abstract

A new dansyl-based chemosensor (2-(4-((5-(dimethylamino)naphthalen-1-yl)sulfonyl)piperazin-1-yl)-N-(quinolin-8-yl)acetamide) (DC) for detecting Cu2+ was synthesized and characterized. DC showed great selectivity to Cu2+ by a fluorescent "on-off" detection method. Job plot, ESI-mass spectroscopy, and 1H NMR titration suggested a 1 to 1 binding mode between DC and Cu2+. The detection limit was determined to be 43 nM, which is greatly below the WHO guidelines. In addition, DC can be applied to real samples and zebrafish imaging. The fluorescence quenching mechanism was proposed as the enhancement of intramolecular charge transfer with calculations.