Naphthalimide−Porphyrin Hybrid Based Ratiometric Bioimaging Probe for Hg2+: Well-Resolved Emission Spectra and Unique Specificity

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• 作者：Chun-Yan Li ; Xiao-Bing Zhang ; Li Qiao ; Yan Zhao ; Chun-Mei He ; Shuang-Yan Huan ; Li-Min Lu ; Li-Xin Jian ; Guo-Li Shen ; Ru-Qin Yu
• 刊名：Analytical Chemistry
• 出版年：2009
• 出版时间：December 15, 2009
• 年：2009
• 卷：81
• 期：24
• 页码：9993-10001
• 全文大小：291K
• 年卷期：v.81,no.24(December 15, 2009)
• ISSN：1520-6882

文摘

In this paper, we unveil a novel naphthalimide−porphyrin hybrid based fluorescence probe (1) for ratiometric detection of Hg²⁺ in aqueous solution and living cells. The ratiometric signal change of the probe is based on a carefully predesigned molecule containing two independent Hg²⁺-sensitive fluorophores with their maximal excitation wavelengths located at the same range, which shows reversibly specific ratiometric fluorescence responses induced by Hg²⁺. In the new developed sensing system, the emissions of the two fluorophores are well-resolved with a 125 nm difference between two emission maxima, which can avoid the emission spectra overlap problem generally met by spectra-shift type probes and is especially favorable for ratiometric imaging intracellular Hg²⁺. It also benefits from a large range of emission ratios and thereby a high sensitivity for Hg²⁺ detection. Under optimized experimental conditions, the probe exhibits a stable response for Hg²⁺ over a concentration range from 1.0 × 10⁻⁷ to 5.0 × 10⁻⁵ M, with a detection limit of 2.0 × 10⁻⁸ M. The response of the probe toward Hg²⁺ is reversible and fast (response time less than 2 min). Most importantly, the ratiometric fluorescence changes of the probe are remarkably specific for Hg²⁺ in the presence of other abundant cellular metal ions (i.e., Na⁺, K⁺, Mg²⁺, and Ca²⁺), essential transition metal ions in celsl (such as Zn²⁺, Fe³⁺, Fe²⁺, Cu²⁺, Mn²⁺, Co²⁺, and Ni²⁺), and environmentally relevant heavy metal ions (Ag⁺, Pb²⁺, Cr³⁺, and Cd²⁺), which meets the selective requirements for biomedical and environmental monitoring application. The recovery test of Hg²⁺ in real water samples demonstrates the feasibility of the designed sensing system for Hg²⁺ assay in practical samples. It has also been used for ratiometric imaging of Hg²⁺ in living cells with satisfying resolution, which indicates that our novel designed probe has effectively avoided the general emission spectra overlap problem of other ratiometric probes.