A simple pyrene based AIEE active schiff base probe for selective naked eye and fluoresence off-on detection of trivalent cations with live cell application

摘要

A simple pyrene based schiff base derivative 2-((pyren-l-ylmethylene)amino)ethanol (PE) has been synthesized via one-pot reaction and its nano-aggregation induced emission enhancement (AIEE) was reported through UV/PL, TEM and DLS studies. Interestingly, PE in CH_3CN revealed the naked eye and fluorescence turn-on sensing responses towards Fe~(3+), Cr~(3+) and Al~(3+) ions, by means of PET and PE-PE~* excimer formation. The 2:1 stoichiometry of sensor complexes PE-M~(3+) (M=Fe/Cr/Al) were calculated from Job's plots based on UV-vis absorption titrations and supported by FTIR and ESI (+Ve) mass analysis. In addition, the binding site of PE-M~(3+) sensor complexes was well established by ~1H NMR titrations and its sensor reversibility was recognized during subsequent addition of M~(3+) ions and PMDTA, respectively. The detection limits (LODs) and the association constant (K_a) values of PE-M~(3+) complexes were calculated by standard deviation and linear fittings. Likewise, quantum yield (Φ_f) calculations, TEM analysis, pH effect and density functional theory (DFT) studies were executed for the PE-M~(3+) sensor complexes. More importantly, confocal fluorescence microscopy imaging in Raw264.7 cells showed that PE could be used as an effective fluorescent probe for detecting Fe~(3+), Cr~(3+) and Al~(3+) ions in living cells.