Design and synthesis of BODIPY-clickate based Hg super(2+) sensors: the effect of triazole binding mode with Hg super(2+) on signal transduction

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 45; no. 6; pp. 2700 - 2708
• Main Authors: Vedamalai, Mani, Kedaria, Dhaval, Vasita, Rajesh, Mori, Shigeki, Gupta, Iti
• Format: Journal Article
• Language: English
• Published: 01.02.2016
• Subjects: Binding; Chelation; Constants; Emission; Fluorescence; Mercury (metal); Toxicity; Triazoles
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c5dt04042f

BODIPY-clickates, F1 and F2, for the detection of Hg super(2+) have been designed, synthesized and characterized. Both F1 and F2 showed hyperchromic shifts in the UV-visible spectra in response to increasing Hg super(2+) concentrations. Hg super(2+) ion binding caused perturbation of the emission quenching process and chelation induced enhanced bathochromic emission of F1 and F2 to 620 nm and 660 nm, respectively. Job's plot clearly indicated that the binding ratio of F1 and F2 with Hg super(2+) was 1 : 1. The NMR titration of BODIPY-clickates with Hg super(2+) confirmed that aromatic amines and triazoles were involved in the binding event. Furthermore, HRMS data of F1-Hg super(2+) and F2-Hg super(2+) supported the formation of mercury complexes of BODIPY-clickates. The dissociation constant for the interaction between fluorescent probes F1 and F2 with Hg super(2+) was found to be 24.4 plus or minus 5.1 mu M and 22.0 plus or minus 3.9 mu M, respectively. The Hg super(2+) ion induced fluorescence enhancement was almost stable in a pH range of 5 to 8. Having less toxicity to live cells, both the probes were successfully used to map the Hg super(2+) ions in live A549 cells.