Preparation and characterization of an efficient and ultra-narrow fluorescence of Eu(III) complex with ultrasensitive sensing to gallic acid

Abstract

A microcrystalline Eu(III) complex is constructed by dehydroabietic acid (DDA) and 1,10-phenanthroline (Phen) by a one-step precipitation method. FTIR, UV, TG and elemental analysis reveal the successful coordination of Eu(III) ions with dehydroabietic acid (DDA) and 1,10-phenanthroline (Phen) through Eu–O and Eu–N bonds, respectively. Comparing with the Eu(III) complex built up by a single ligand of Phen, the Eu(III) complex with DDA and Phen exhibits an enhanced absolute quantum yield with the maximum of 95.76%, and a decreased full width at half maxima of 5D0 → 7F2 transition with the 2.56 nm at 308 K. After introducing DDA into coordinate structure, not only the C–H bending vibrations of the heterocyclic rings in Phen is suppressed, but also the Huang-Rhys factor and the reorganization energy of the Eu(III) complex decrease. The sensing performance of the Eu(III) complexes based on DDA and Phen can detect gallic acid effectively in ethanol solution between 9.48 × 10−3 mM and 6.78 × 10−2 mM with a good linear relationship.