A triphenylamine based fluorescent probe for Zn2+ detection and its applicability in live cell imaging

A triphenylamine-based Schiff base (TPOH) was synthesized as a good fluorescent sensor for recognizing of Zn2+. The fluorescence intensity of the probe TPOH was significantly enhanced after coordination with Zn2+ with a yellow fluorescence at the excitation wavelength of 525 nm. In MeOH-H2O (3:7 in v/v) solution, the probe showed excellent selectively for Zn2+ over most other competing ions, which exhibited an Intramolecular Charge Transfer (ICT) mechanism in the recognition procedure. The reaction stoichiometry of 1:1 between TPOH and Zn2+ was determined based on the Job’s plot and 1H NMR spectra, respectively. The HeLa cells maintained over 95% of viability after 24 h exposure to TPOH, which identified the extremely low toxic of TPOH and can be used for in vivo cell imaging.