Dicyanostilbene-derived Two-photon Fluorescence Probe for Free Zinc Ions in Live Cells and Living Tissues

摘要

A novel two-photon fluorescence probe for Zn2+ derived from dicyanostilbene as a two-photon fluorophore and 4-(pyridine-2-ylmethyl) piperazine as a novel Zn2+ ligand was developed, and its structure was characterized by H-1 NMR, IR and elemental analysis. By UV-Vis absorption and absorption-titration experiments, one-and two-photon excited fluorescence experiments in femtosecond pulses, as well as cell-imaging and tissue-imaging experiments, the probe showed a 72. 5-fold fluorescence enhancement in response to Zn2+, a large two-photon action cross-section (580 GM), a noncytotoxic effect, and pH insensitivity in the biologically relevant range, with a dissociation constant(K-d(TP)) of (0. 52 +/- 0. 01) mu mol/L. The probe could detect free Zn2+ ions selectively in live cells for about 1500 s and in living tissues at a depth of 80-150 mu m without interference from other metal ions or membrane-bound probes.

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