Novel anthracene- and pyridine-containing Schiff base probe for selective "off-on\'\' fluorescent determination of Cu2+ ions towards live cell application

Abstract

The novel anthracene- and pyridine-containing Schiff base derivative 2-(2-(anthracen-9-ylmethylene)-hydrazinyl) pyridine (AP) has been synthesized via one-pot reaction and its fluorescent "off-on\'\' detection of Cu2+ ions, via PET-based mechanism, is reported. The 1 : 1 stoichiometry of AP center dot center dot center dot Cu2+ sensor complex was calculated from Job\'s plot based on PL titrations and supported by ESI (+Ve) mass spectral analysis. In addition, the binding sites of AP center dot center dot center dot Cu2+ sensor conjugate were supported by H-1 NMR titration. The detection limit (LOD) and association constant (Ka) of AP center dot center dot center dot Cu2+ complex were obtained by standard deviation and linear fittings. Furthermore, quantum yield (Ff), SEM analysis, pH effect, FTIR interpretation and density functional theory (DFT) studies were conducted for the AP center dot center dot center dot Cu2+ sensing conjugate. More decisively, confocal fluorescence microscopy imaging from Raw264.7 cells indicated that AP could be used as an effective fluorescent probe for the analysis of Cu2+ ions in living cells.