A multichannel thiacalix[4]arene-based fluorescent chemosensor for Zn²⁺, F⁻ ions and imaging of living cells

Abstract

The fluorescent sensor (3) based on the 1,3-alternate conformation of the thiacalix[4]arene bearing the coumarin fluorophore, appended via an imino group, has been synthesised. Sensing properties were evaluated in terms of a colorimetric and fluorescence sensor for Zn²⁺ and F⁻. High selectivity and excellent sensitivity were exhibited, and ‘off-on’ optical behaviour in different media was observed. All changes were visible to the naked eye, whilst the presence of the Zn²⁺ and F⁻ induces fluorescence enhancement and the formation of a 1:1 complex with 3. In addition, 3 exhibits low cytotoxicity and good cell permeability and can readily be employed for assessing the change of intracellular levels of Zn²⁺ and F⁻.

Keywords:

• Thiacalix[4]arene derivative
• colorimetric and fluorescent sensor
• Zn²⁺
• F⁻
• cell imaging

Acknowledgements

This work was supported by the Natural Science Foundation of China [grant number 21165006]; the Fund of the International Cooperation Projects of Guizhou Province [grant number 20137002]; ‘Chun-Hui’ Fund of Chinese Ministry of Education [grant number Z2011033], [grant number Z2012053]. The EPSRC is thanked for financial support (Overseas Travel award to CR).