期刊
DYES AND PIGMENTS
卷 99, 期 3, 页码 561-570出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.dyepig.2013.06.022
关键词
Squaraines; Cyanines; Fluorescence lifetime; IgG-conjugates; Quantum yields; Aggregation
资金
- Science and Technology Centre in Ukraine [P313, P548]
- National Academy of Sciences of Ukraine [0113U001410]
Unlike cyanine dyes, which are widely used as fluorescent probes and labels for biomedical applications squaraine dyes are less investigated. A series of monoreactive, water-soluble, squaraine dyes with two aromatic sulfo groups and up to 3 sulfobutyl groups was synthesized and the spectral properties of these dyes were compared to dicarbocyanines of identical structure. Compared to the cyanines in aqueous solutions the squaraine dyes absorb and emit at shorter wavelengths (630-636 nm/639-645 nm vs. 647-653 nm/665-672 nm), have higher molar absorptivities (284,000-333,000 M-1 cm(-1) vs. 242,000-260,000 M-1 cm(-1)), lower fluorescence quantum yields (4.3-9.4% vs. 27-32%) and lower fluorescence lifetimes (0.2-0.3 ns vs. 1.0-1.2 ns) but the quantum yields and lifetimes substantially increase when bound to proteins (Bovine Serum Albumin (BSA) or antibodies, immunoglobulin G (IgG)). Squaraines with two aromatic sulfo groups show no aggregation tendency up to concentrations of 2 x 10(-4) M while the corresponding cyanine dye is free of aggregation up to 5 x 10(-4) M. The increase in the number of sulfobutyl groups bears a strong influence on the aggregation tendency of both dye classes upon covalent labeling to BSA and IgG resulting in increased quantum yields and lifetimes of the protein conjugates. Compared to cyanines, squaraine dyes exhibit higher photostabilities and much higher sensitivity of the quantum yields and fluorescence lifetimes toward the microenvironment and are therefore better suited as fluorescence sensors. (C) 2013 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据