A novel fluorescence probe based on triphenylamine Schiff base for bioimaging and responding to pH and Fe 3 .

A novel fluorescence probe 1 based on triphenylamine was synthesized and characterized by NMR, IR, high resolution mass spectrometry and elemental analysis. Its fluorescence was quenched when pH below 2. There was a linear relationship between the fluorescence intensity and pH value ranged from 2 to 7. And its fluorescence emission was reversibility in acidic and alkaline solution. Furthermore, it exhibited remarkable selectivity and high sensitivity to Fe3+ and was able to detect Fe3+ in aqueous solution with low detection limit of 0.511μM. Job plot showed that the binding stoichiometry of 1 with Fe3+ was 1:1. Further observations of 1H NMR titration suggested that coordination interaction between Fe3+ and nitrogen atom on CN bond promoted the intramolecular charge transfer (ICT) or energy transfer process causing fluorescence quenching. Additionally, 1 was also able to be applied for detecting Fe3+ in living cell and bioimaging.