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汞化合物的应用非常广泛,它们广泛应用于化工、制药、冶金、电子仪器、军事等高新技术领域,还可用于制造科学测量仪器(如压力表、温度计等)、电子电器产品、化工产品、催化剂、汞灯、电极等。然而,由于其在工业和制造业中被大量使用,其造成的环境污染越来越严重[1-2]。与其它污染物不同的是,汞不能被生态系统本身的物理、化学或生物手段降解,而是以生物和非生物两种形式在自然界中迁移和积累。由于其毒性极强,易于渗透,难以代谢,在生物体内富集后容易造成长期伤害[3-5]。例如,汞离子可以在人体内长期存在,严重危害中枢神经系统、消化系统和肾脏等。此外,其对呼吸系统,皮肤、血液和眼睛等也有较大危害[6-7]。因此,开发一种能够快速、简洁、准确检测汞离子的方法具有十分重要的意义。
传统的汞离子检测方法主要有原子吸收光谱法(AAS)、原子发射光谱法(AES)、电感耦合等离子质谱法(ICP-MS)、高效液相色谱法(HPLC)、X-射线荧光光谱法(XRF)以及电化学方法等,这些方法具有灵敏度高、特异性好、应用广泛等优点[8-10]。但这些方法往往需要昂贵的设备,并且样品的预处理比较复杂。与传统的检测方法相比,荧光探针法不仅操作简便、检测速度快、特异性强,而且还特别适合于在细胞微环境中进行检测[11-15]。
本文以10-苯基-1,4-二氧杂-7,13-二硫杂-10-氮杂环戊烷为汞离子检测单元、(3,5,5-三甲基环己-2-烯亚基)丙二腈为荧光团,构建了一个具有红色荧光信号的比色型汞离子荧光探针,并研究了该探针对汞离子的响应以及其在生物体中的荧光成像应用。
汞离子比色型荧光探针的合成与性质
Synthesis and properties of colorimetric fluorescent probe for mercury ions
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摘要:
汞化合物在促进工业和制造业快速发展的同时,也带来了严重的环境污染。由于其毒性极强,易于渗透,难以代谢,在生物体内富集后容易造成长期伤害。因此,开发一种能够快速、简洁、准确检测汞离子的方法具有十分重要的意义。为此,本文发展了一个基于氧硫杂冠醚配体的汞离子特异性的比色型荧光探针。该探针能够通过比色及荧光高选择性检测汞离子,且干扰性小、灵敏快捷。探针可以与汞离子形成1: 1络合物,该络合物可以在碘离子作用下将汞离子从配合物中解离,利用该平衡可以对汞离子进行定量检测。特别值得提及的是,该探针能够用于细胞及活体中汞离子的可视化检测。
Abstract:While mercury compounds promote the rapid development of industry and manufacturing industry, they also bring serious environmental pollution. Due to its high toxicity, easy penetrability and difficult metabolism, it is easy to cause long-term damage after aggregation in organisms. Therefore, it is of great significance to develop a rapid, simple and accurate method to detect mercury ions. Accordingly, a mercury-ion specific colorimetric fluorescent probe based on oxy-thio-crown ether ligand was developed. The probe could detect mercury ions through colorimetry and fluorescence with high selectivity, low interference, high sensitivity and quick response time. Moreover, the formed 1: 1 complex between probe and mercury ions could be dissociated in the presence of iodide ions, and the equilibrium could be applied in quantitative detection of mercury ions. In particular, the probe could be used to track mercury ions in living cells and in vivo.
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Key words:
- fluorescent probe /
- mercury ions /
- colorimetric /
- bioimaging
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图 2 探针MNC(10−5 mol·L−1)在DMSO-H2O(V/V = 5:95)中分别加入金属离子Cu2+、Zn2+、Mn2+、Ni2+、Cd2+、Pd2+、Pb2+、Co2+、Hg2+、Na+、K+、Mg2+、Ca2+、Li+、Al3+(10−4 mol·L−1)后的紫外-可见吸收光谱(a)、颜色变化(b)和荧光光谱(c);(d)MNC和MNC-Hg在不同pH值下的最大荧光强度变化。λex = 550 nm
Figure 2. The UV-visible absorption spectra (a), color changes (b) and fluorescence spectra (c) of MNC (10−5 mol·L−1) in the mixture of DMSO-H2O (V/V = 5:95) in the presence of 10−4 mol·L−1difference metal ions(Cu2+, Zn2+, Mn2+, Ni2+, Cd2+, Pd2+, Pb2+, Co2+, Hg2+, Na+, K+, Mg2+, Ca2+, Li+, and Al3+); (d) the maximum fluorescence intensity change of MNC (10−5 mol·L−1) and MNC-Hg at different pH values. λex = 550 nm
图 3 在DMSO-H2O(V/V = 5:95)体系中加入不同浓度的Hg2+(0−7×10−5 mol·L−1)后,探针MNC(10−5 mol·L−1)的吸收光谱(a)和荧光光谱(b),λex= 550 nm;(c)和(d)表示MNC的最大荧光强度变化(I672/I0)与Hg2+浓度的关系。
Figure 3. The UV-visible absorption spectra (a) and fluorescence spectra (b) of MNC (10−5 mol·L−1) in the mixture of DMSO-H2O (V/V = 5:95) in the presence of difference concentrations of Hg2+ (0 − 7×10−5 mol·L−1), λex = 550 nm; (c) and (d) represent the relationship between the maximum fluorescence intensity change (I672/I0) of MNC and the concentration of Hg2+.
图 4 在DMSO-H2O(V/V = 5:95)体系中加入不同浓度的KI后,MNC-Hg的紫外吸收光谱(a)和荧光光谱(b), λex = 550 nm;(c)和(d)表示MNC-Hg的最大荧光强度变化(I672/I0)与KI浓度的关系。
Figure 4. The UV absorption (a) and fluorescence (b) spectra of MNC-Hg in DMSO-H2O ( V/V = 5:95) system after adding KI with different concentrations, λex = 550 nm; (c) and (d) represent the relationship between the maximum fluorescence intensity change (I672/I0) of MNC-Hg and the concentration of KI.
图 5 (a)不同浓度MNC孵育后Hela细胞的存活率;(b)Hela细胞经MNC(10−5 mol·L−1)以及MNC(10−5 mol·L−1)和10−4 mol·L−1 Hg2+共孵育后的共聚焦显微镜图像(左)明场图像,(中)红色通道图像,(右)合并图像。
Figure 5. (a) The survival rate of Hela cells incubated with different concentrations of MNC; (b) Confocal laser microscope images of Hela cells incubated with MNC (10−5 mol·L−1) in the absence of Hg2+ and in the presence of Hg2+ (10−4 mol·L−1). Left: bright field; middle: red channel; right: merged image.
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