Triphenylamine-based Schiff bases as the High sensitive Al3+ or Zn2+ fluorescence turn-on probe: Mechanism and application in vitro and in vivo

Two novel similar structural triphenylamine-based Schiff base fluorescent probes (L1/L2) were designed, prepared and characterized. Distinctive recognition mechanisms of L1 and L2 toward Al3+ and Zn2+ have been established by UV/vis, fluorescence spectra, mass spectra and 1H NMR studies, respectively. To further explore their utility in biological system, L2 was selected as a probe for live cell endogenous Zn2+ indicator and showed superb sensitivity on Zn2+ intracellular distribution. Furthermore, L2 was employed to selectively detect Zn2+ in live tissues at both extracellular and intracellular level, qualitatively indicated varies zinc concentration as a function of different organs.