双氰基二苯代乙烯型双光子荧光汞离子探针

分别以双氰基二苯代乙烯(DCS)和双2-(2-羟乙基硫基)乙基]氨(HSA)为双光子荧光团和汞离子受体,合成了双光子荧光汞离子探针(DHg),并对其结构进行了分析.实验结果表明,DHg在甲苯、乙腈和水中的荧光量子产率(Φ)分别为0.78,0.42和0.20,对汞离子的络合常数通过单、双光子荧光滴定分别拟合为lg K=5.47±0.02和lg K=5.34±0.02.DHg在水溶液中对汞离子具有优良的选择性和高的灵敏性,可用于中性环境中汞离子的检测.DHg的双光子吸收截面(δTPA)在水溶液中高达840 GM,可用于细胞中汞离子的检测与成像.

Dicyanostilbene-derived Two-photon Fluorescence Probe for Mercury Ions

A novel water-soluble two-photon fluorescent probe for Hg2+( DHg) derived from dicyanostilbene (DCS) as a two-photon fluorophore and bis2-(2-hydroxyethyl sulfanyl) ethyl]amino group(HAS) as a novel Hg2+ ligand was developed, and its structure was analyzed and identified. The results of UV-Vis absorption and absorption-titration experiments, one-and two-photon excited fluorescence experiments, as well as cellimaging and tissue-imaging experiments showed that the probe has a very high sensitivity and selectivity for the detec-tion of Hg2+ in water. It can be used to detect trace Hg2+ in neutral or basic aqueous solution(pH=7—12), and its binding constant(lgK) for Hg2+ was determined from the one- and two-photon fluorescence-titration curves to be lgK=547±002 and lgK=534±002, respectively. Nitrogen atom property and the sulfur atom number on the ionophore are believed to be responsible of the unique selectivity of probe DHg for Hg2+. The fluorescent quantum yields of DHg in toluene, acetonitrile and water are 078, 042 and 020, respectively, and its two-photon absorption cross-section(δTPA ) is as high as 840 GM in aqueous solution. The probe could selectively detect free Hg2+ ions in live cells without interference from other metal ions and the membrane-bound probes. Undoubtedly, the probe is an ideal two-photon excited fluorescence bioimaging candidate.