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题名	硫化氢荧光探针分子的设计合成与检测研究
作者	刘春霞
学位类别	硕士
答辩日期	2014-05
授予单位	中国科学院研究生院
授予地点	北京
导师	魏国华
关键词	荧光探针 硫化氢 检测 2-（2ˊ-羟基苯基）苯并咪唑 Fluorescent Probe Hydrogen Sulfide Detection 2- (2 '- hydroxy phenyl) benzimidazole
其他题名	Design、Synthesis and Testing Study of Fluorescence Probe Molecules for Hydrogen Sulfide
学位专业	环境科学
中文摘要	硫化氢（H2S）是一种重要的气体信号分子，与许多重要的生理病理过程息息相关。因此对其进行准确的检测十分重要。荧光分子探针能够将分子识别信息转换成仪器可测量的荧光信号，具有灵敏度高、选择性好、操作简单和可实时原位检测 (荧光成像技术)等优点，在H2S的检测中得到了广泛的关注。H2S特殊的化学性质如还原性、亲核性以及和Cu2+强的结合能力等常常被用于H2S荧光探针的设计。       荧光素由于具有较高的消光系数、较好的荧光量子产率、较长的发射光谱和易于修饰等优点，被广泛的应用于荧光探针的设计。本文利用H2S能够将叠氮还原成氨基，同时分子内关环，打开荧光素螺环的原理，设计合成了以荧光素为母体，叠氮基为H2S反应位点的“off-on”型荧光探针。探针自身以螺旋内酯的形式存在，几乎没有荧光。H2S将探针中的叠氮基还原生成含有氨基的中间体，继而发生分子内酰胺化反应，使酯键断裂，原位生成开环的荧光素分子，产生强荧光，同时伴随着颜色从无色到亮黄色的改变。该探针能够高选择性的识别H2S，常见阴离子和还原性硫醇分子几乎无干扰；在H2S浓度为0-50 μmol/L的范围内，探针荧光强度和H2S浓度之间有很好的线性关系，对H2S的检测限为10 μmol/L。       2-（2ˊ-羟基苯基）苯并咪唑（HBI）是一种重要的荧光化合物，可以通过分子内质子转移（ESIPT）过程，发射双重荧光峰，具有Stokes位移大、荧光量子产率高的特点，因此在荧光检测领域应用广泛。如果对HBI结构中的羟基进行修饰，就会改变其ESIPT过程，导致分子的荧光性质发生相应的改变。基于上述原理，本论文通过在HBI羟基上引入苯呋咱（NBD）基团，设计合成了新型H2S荧光探针。由于H2S有较强的亲核性，使探针中NBD醚键发生硫解，重新生成了HBI分子，发出荧光。同时体系颜色由淡黄色变成紫色，能够对H2S进行可视化检测，可视化检测限为3 μmol/L。探针对H2S表现出了良好的荧光选择性和很快的响应速度（5 min），在较宽的pH（6~9）范围内，仍然表现出较好的荧光性能，荧光检测限为6 μmol/L。
英文摘要	Hydrogen sulfide (H2S) is an important gaseous transmitter, closely related to a number of pathophysiological processes. Thus, it is important to detect it accurately. Fluorescent probes can transfer molecular recognition events into fluorescence signals which can be measured by instrument. Because of the advantages of high sensitivity, nice selectivity, simple operation and real-time detection in situ (fluorescence imaging）, fluorescent probes have received considerable attentions. The special chemical properties of H2S, such as reducibility, nucleophilicity and strong combination with Cu2+ are often employed in the design of fluorescent probes.        Fluorescein is used widely as the fluorophore in fluorescent probes, owing to its excellent spectroscopic properties such as large molar extinction coefficient, high fluorescence quantum yield, long emission spectra and easy modification. We designed and synthesized an “off-on” H2S probe based on the reducibility of H2S, using fluorescein as the fluorophore and azido group as the reaction site. The new probe itself exists in the spirallactone form, with almost no fluorescence. The azido moiety was reduced by H2S into the corresponding amine intermediate, followed by intramolecular amidation and cleavage of the ester bond to release the open-ring fluorescein in situ. The probe shows strong fluorescence accompanied by a color change from colorless to light yellow during the sensing process. The linear range covers from 0-50 μmol/ L with a detection limit of 10 μmol/ L.       2- (2 '- hydroxy phenyl) benzimidazole (HBI) is an important fluorescent compound in the field of fluorescence detection, because of large Stokes shift and high fluorescence quantum yield via intramolecular proton transfer (ESIPT). If the hydroxyl group of HBI was modified, ESIPT process of HBI would be affected, resulting in its fluorescence properties change. Based on the above principles, we synthesized another H2S probe by coupling HBI and benzoxadiazol (NBD). The nucleophilicity of H2S caused thiolysis of the NBD ether bond to regenerate HBI with fluorescence. At the same time, the color of the testing system changed from light yellow to purple. The new colorimetric and fluorescent “turn-on” probe can realize visual detection of H2S with detection limit at 3 μmol/L. It shows good selectivity and fast response speed (5 min) for H2S, and still exhibits good fluorescence properties in a wide range of pH from 6 to 9. The detection limit is as low as 6 μmol/L.
公开日期	2015-07-07
内容类型	学位论文
源URL	[http://ir.rcees.ac.cn/handle/311016/15704]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	刘春霞. 硫化氢荧光探针分子的设计合成与检测研究[D]. 北京. 中国科学院研究生院. 2014.

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