| It’s well known that heavy metals such as mercury have high biological toxicity. The accumulation of mercury ion in human body can induce various diseases, such as prenatal brain damage and Minamata disease. As a result, development of efficient detecting mercury is of great importance, fluorescence spectrometry has received considerable attention because of its fast, efficient detection of trace amounts of mercury. There are two main types of fluorescent probes including coordination and reaction-based probe reported currently. However, the probe for mercury based on Coordination showed relatively low selectivity over competing metal ions, as a result,"reactive" molecular sensor have attracted more and more attention owing to its extremely high selectivity, the existing developed mercury probes have several disadvantages, containing their poor water-solubility and weak capability to exclude the interference of anion, meantime the probe based on irreversible chemical reactions are not reusable. In order to slove the problems exist in the probe above, in this wok, the specific reaction of giving rise to corresponding furan ring structure induced by mercury, was used in the design of new reaction-based mercury probe, which can exclude the interference of anion effectively, this reaction site was introduced into different fluorophores, and a series of mercury probe was synthesized, whose recognition performance towards mercury were studied. The specific contents and results are as follows:1. The synthesis of probe containing naphthyl group:the probe HI was synthesized and the recognition performance of HI towards mercury was studied by fluorescence titration. It was found that the fluorescence enhanced significantly upon the addition of mercury, the recognition system can effectively eliminate the interference of anions, however the copper ions and iron ions quenched the fluorescence of the system, and meanwhile the reaction time was up to20hours, which is not conducive in practical application. After the the NMR titration, H1turned into the corresponding compound Hg-H1upon the addition of mercury. The recognition reaction of H1and mercury derived from the destruction of the intramolecular hydrogen bond of H1.2. The synthesis of probe containing coumarin group:The probe L1was synthesized and the recognition performance of L1towards mercury was studied by fluorescence titration. It is found that the fluorescence of the system about10times adding to mercury during the study, the system can effectively exclude the interference of the anion and cation, and meantime it can effectively detect mercury in the actual water sample, but the fluorescence of the probe is not strong, while it takes half an hour for the reaction. To verify that the reaction process, the corresponding NMR titration was carried out and the probe L2was synthesized, prove that P1was produced by the reaction of between L1and mercury, the recognition of L1derived from P1produced by the reaction of between L1and mercury, leading to the molecular plane rigidity enhancement. Later for overcoming the defects of L1which has weak fluorescence, the modification of the fluorescence properties of L1was carried out, fluorescent probes L3-L7were designed and synthesized, however these probes can not be spontaneous reaction with mercury.3. The synthesis of probe containing naphthalimide group:the probe N1was synthesized and the recognition performance of N1towards mercury was studied by fluorescence titration and UV-vis titration. Upon addition of mercury, there is a remarkably fluorescence enhancement over100fold, the color changed from pale yellow to colorless simultaneously. The probe is water-soluble, and can achieve instantaneous detection, which can be applied to the detection of the concentrations of mercury in living cells, while the corresponding NMR titration revealed that upon the addition of NaBH4, the reaction is reversible. It shows that the probe N1has extremely significant prospect in practical application. |
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