An efficient Hg2+ ensemble based on a triazole bridged anthracene and quinoline system for selective detection of cyanide through fluorescence turn-off-on response in solution and live cell

A simple triazole bridged molecular probe containing anthracene and quinoline moieties has been designed and synthesized as a fluorescent molecular probe (7). The photophysical behavior of the probe 7 has been examined and tested for the recognition of ions in partial aqueous medium and HeLa cell. The probe 7 has shown strong affinity for Hg2+ and has been utilized to develop a stable ensemble, 7 center dot Hg2+. The ensemble, 7 center dot Hg2+ upon interaction with different class of anions showed high affinity for cyanide with similar to 16 fold fluorescence enhancement and high limit of detection, 1.25 mu M. The live cell imaging studies showed that ensemble 7 center dot Hg2+ is capable to detect CN-intracellularly. The analytical applicability of the probe for Hg2+ and CN-has been tested on the test paper strips. Additionally, the naked eye sensitive On-Off-On switching behavior of 7 has been utilized to mimic the function of a sequential logic circuit at molecular level. The H-1 NMR titration, ESI-MS spectroscopy and DFT calculation confirms the binding behavior between 7 and Hg2+. (C) 2017 Elsevier B. V. All rights reserved.