A highly selective and sensitive fluorescence probe with A-π-D-π-A structure for detection of Ag+

Abstract

A novel triphenylamine derivative, 4,4′-bis-([1,10]phenanthrolin-2-yl) imidazo -triphenylamine (IPTPA) with an A-π-D-π-A structure, has been synthesized and characterized. The UV absorption, single and two-photon fluorescence spectra showed that IPTPA was highly sensitive to Ag+ with a lower detection limit of 3.97 nmoL/L and a moderate binding constant of 2.16 × 105/M at room temperature. The two-photon active cross-section of IPTPA was calculated with a value of 94.68 GM at 800 nm in the tris-HCl buffer solution. The binding mechanism between IPTPA and Ag+ were explored by the Job plot, ESI-MS and 1H NMR. The A-π-D-π-A structure of IPTPA was substituted by the A-π-D-π-D structure of IPTPA-Ag to improve the fluorescence. Furthermore, the fluorescence microscopy images indicated that IPTPA could detect Ag+ in living cells.