文献类型：期刊文献

英文题名：Near-infrared cell-permeable Hg2+-selective ratiometric fluorescent chemodosimeters and fast indicator paper for MeHG+ based on tricarbocyanines

作者：Guo, Zhiqian[1]; Zhu, Weihong[1]; Zhu, Mingming[2]; Wu, Xumeng[1]; Tian, He[1]

机构：[1] Key Laboratory for Advanced Materials, Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China; [2] Department of Gastroenterology, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200001, China

年份：2010

卷号：16

期号：48

起止页码：14424

外文期刊名：Chemistry - A European Journal

收录：EI(收录号：20110213580419)

语种：英文

外文关键词：Dosimetry - Metal ions - Thioureas - Mercury compounds - Emission spectroscopy - Mercury (metal) - Infrared devices

摘要：Three tricarbocyanine dyes (IR-897, IR-877, and IR-925) with different thiourea substituents that function as dosimeter units through specific Hg 2+-induced desulfurization have been demonstrated in a fast indicator paper for Hg2+ and MeHg+ ions. In comparison with available Hg2+-selective chemodosimeters, IR-897 and IR-877 show several advantages, such as convenient synthesis, very long wavelengths falling in the near-infrared (NIR) region (650-900nm) with high molar extinction coefficients, a ratiometric response, and quite low disturbance with Ag + and Cu2+ ions. They exhibit large redshifts, which result in a clear color change from deep blue to pea green that can be easily monitored by the naked eye for a convenient indicator paper. In emission spectra, they display a characteristic turn-off mode at 780nm and turn-on mode at 830nm with titration of Hg2+ ions. Remarkably, the signal/noise (S/N) ratio with other thiophilic metal ions (Ag+ and Cu 2+) is greatly enhanced with ratiometric measurement of two channels: excitation spectra mode (I810nm/I670nm, monitored at 830nm) and emission spectra mode (I830nm/I780nm, isosbestic absorption point at 730nm as excitation). The distinct response is dependent upon the electron-donating effect of the thiourea substituents; that is, the stronger the electron-donating capability of the thiourea substituents, the faster the Hg2+-promoted cyclization. Additionally, experiments with living SW1116 cells show that these three tricarbocyanine dyes with low toxicity can exhibit special characteristics that are favorable for visualizing intracellular Hg2+ and MeHg+ ions in biological systems, including excellent membrane permeability, minimal interfering absorption and fluorescence from biological samples, low scattering, and deep penetration into tissues. Copyright ? 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.