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Studies On The Fluorescein Based Fluorescent Chemosensors For Heavy Metal Ions

Posted on:2008-01-21Degree:DoctorType:Dissertation
Country:ChinaCandidate:X M MengFull Text:PDF
GTID:1118360212999069Subject:Organic Chemistry
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This dissertation firstly reviewed the research history and recent development of the ion enrolled photo-introduced electron transfer (PET) reaction. And then the paper focused on the application of this kind PET reaction, i.e. the development of chemosensors for metal ions. Currently there is great in interest in the development of fluorescent sensors for quantifying and exploring the role of heavy metal ions in medicine and biology as well as in the environment. Thus, in this dissertation, several kind of fluoresccin based chemosensors for heavy metal ions were designed and synthesized. The selectivity and sensitivity of the new sensors to the target ions were carefully studied.Two novel fluorescent Zn2+ chemosensors were designed and synthesized in four steps for inexpensive staring materials. The new sensors exhibited very strong fluorescence responses to Zn2+ and had remarkably high selectivity to Zn2+ over other metal inos including Mg2+, Ca2+, Ni2+, Cu2+, and Cd2+. These two new molecules could be used as low-priced yet high quality Zn2+ chemsensors.Then, the research interest was shifted to the developing of new chemosensors for the high toxic Hg2+. The fluoresccin group was equipped dithia-dioxa-monoaza 15-crown-5 unit, which shows high selectivity to Hg2+, to form a water soluble molecular. The test result indicated that the newly designedâ– fluoresecin derivative exhibited high selectivity to Hg2+ over other metal ion under physiological conditions. This research indicated that replacement of the oxygen atom in the suitable size crown ether by sulfur atom will lead to great selectivity to Hg2+.According to the literature, a high mercury-philic carbamodithioate moiety, which was seldom used as Hg2+ receptor, was introduced into fluorescein derivatives. The flowing test result suggested that the new compounds can be used as efficient Hg2+ chemosensor in common situations. Based on the about result, the new Hg2+ sensors were applied to monitor the Hg2+ concentrations in real samples without expensive instruments. Reasonable results were obtained compared with the results from the traditional method, i.e., atom absorption method.
Keywords/Search Tags:Chemosensors
PDF Full Text Request
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