【作者】 郭柯馨；

【导师】 樊江莉； 彭孝军；

【作者基本信息】 大连理工大学 ， 应用化学， 2009， 硕士

【摘要】 汞是最具有毒性和危险性的重金属元素之一,而汞的污染和传播主要是通过火山喷发,采矿,固体废弃物的焚烧和矿物燃料的消耗等途径进行的,尤其值得注意的是,汞可以通过生物富集作用,集中在食物链中,这样会引起危害人类健康的许多疾病。因此,生物体中或环境中汞的检测引起人们的极大关注。最近几十年,已经报道多种Hg²⁺的分析方法,其中荧光光谱法最受关注。荧光探针能将分子间的相互作用转变成荧光信号传递给外界,从而帮助我们认识和理解微观世界的状态、性质、及其变化规律,兼备便捷、专一和灵敏的优点,并能对化学体系和生命体系中的研究对象进行适时原位检测。因此,利用荧光探针来检测环境或生命体内的Hg²⁺,成为超分子化学以及生物医学发展领域中重要的研究课题之一。本论文在组内工作的基础上,对原有的探针进行了改进,设计合成了新的Hg²⁺探针B2。B2在HEPES缓冲溶液中,对Hg²⁺有较高的选择性,不受其他金属阳离子的干扰。由于醚链末端引入的羧基,增大了B2对Hg²⁺的络合能力,使得B2不再受阴离子的干扰。B2的检测限为72 nM,对10 ppb级别的Hg²⁺有较好的响应。B2的酯化形式,具有较好的细胞穿透能力,可以应用于PC12细胞中显微成像,实现了活细胞内Hg²⁺成像。另外,将不同的含硫开链冠醚引入到HOMO能级较BODIPY更低的罗丹明染料上,设计合成了一系列的Hg²⁺探针:R-A-E,R-A,R-OAc,R-OH。探针对Hg²⁺有不同的响应程度,其中R-A的选择性最好,抗各种阳离子、阴离子的干扰能力最强,对Hg²⁺有较强的络合能力,较低的检测限。更重要的是,R-A在较宽的pH范围内,对Hg²⁺的响应不受质子的干扰。R-A对应的酯化形式,R-A-E,也可以用在PC12细胞和Hela细胞中显微成像,在低浓度下可以在活细胞中对Hg²⁺进行检测。更多还原

【Abstract】 Mercury is one of the most toxic and dangerous heavy metal elements.Mercury contamination is widespread and occurs through various processes,e.g.volcanic emissions, mining,solid waste incineration,and the combustion of fossil fuels.Of particular concern,is the concentration in the food chain,and bioaccumulation of mercury in animals.It is frightening that mercury-containing chemicals have been linked with a number of human health problems.Thus,much attention has been focused on developing new methods to monitor Hg²⁺ in biological and environmental samples.Recently,much method has been made to detect mercury.Fluorescent spectrometry is the most promising one.Compared with traditional methods for the detection of mercury,the fluorescent probes have attracted much attention over the years for its many inherent merits including high specifity and high sensitivity.This technology has been widely used for the real-time in situ detection of the molecular events both in the chemical and biological systems. Hence,exploring fluorescence sensors for detection of mercury in biological and environmental samples is one of the most important research subjects in supramolecular chemistry and biomedicine.Based on the previous work in our group,an improved fluorescent chemosensor for Hg²⁺, B2,was synthesized.In HEPES buffer solution,B2 exhibits selective fluorescence enhancement towards Hg²⁺ over other metal ions.The fluorescence enhancement was unaffected by anions existing in environment and organism because of the introduction of carboxyl-thiol moieties.B2 shows high sensitivity to Hg²⁺ in a concentration of ppb range with detection limit of 77 nM.B2-ester,the membrane-permeable ethyl ester,is able to be hydrolyzed to B2 in vivo,and successfully applied to image intracellular Hg²⁺ in living cells.In addition,different acyclic thioesters were intuduced into the fluorophore of rhodamine and a serious of Hg²⁺ sensors,R-A-E,R-A,R-OAe and R-OH were obtained.The four sensors showed fluorescence response towards Hg²⁺ in different degree.R-A shows high selectivity and sensitivity towards Hg²⁺,and the fluorescence enhancement is unaffected by other metal ions and anions.In a wide pH range,the response of R-A towards Hg²⁺ is unaffected by proton.The ethyl ester form of R-A,R-A-E,is successfully applied to image intracellular Hg²⁺ in living PC12 and Hela cells.更多还原