| Iron is an important element in our lives. Iron has hematopoietic function and not only involves in the synthesis of hemoglobin, cytochrome and various enzymes, but also plays a role in transporting oxygen and nutrients in blood. Too much or too little iron exist in body is detrimental to the human body. Traditional methods for detecting iron are time-consuming and laborious, but fluorescence detection means is easy and economical. Among numerous fluorescence detection means, the detection method of fluorescent probe based on the aggregation-induced emission is rarely reported.Fluorescent molecular probes designed in this thesis were based on aggregation-induced emission. Two novel fluorescent molecular probes M1and M2were designed and synthesized successfully in this thesis and their structure had been confirmed by1H NMR,13C NMR, ESI-MS. Designing ideas of two fluorescent Probe were based on tetraphenyl ethylene and2-pyridine methyl-2-thiophene methyl amine and two fluorescent probe were both synthesized by click reaction. As the structure of fluorescent probe, the tetraphenyl ethylene was as the fluorophore while the2-pyridine methyl-2-thiophene methyl amine was as the identify group.The study of response to metal ions of two fluorescent probe had been done by ultraviolet-visible spectrum and fluorescent spectrum methods. M1had a specific fluorescence quenching response to Fe3+, while M2could not be an ideal fluorescent probe due to instability caused by its poor solubility.Ideal testing solvent and its proportion was firstly chose in the experiments of fluorescence spectra and UV spectra of M1. It was found that M1had a specific fluorescence quenching response to Fe3+and the fluorescence intensity reduced by95percent. The presence of other metal ions did not interfere with the recognition of M1for Fe3+. Coordination of M1with Fe3+was considered to be1:2through the fluorescence spectra, UV spectra and Job test. The detection limit was calculated to be0.7μ.M. The conclusion that the existence of different anions of iron salts did not interfere with the recognition of Ml for Fe3+was got from the phenomenon that the fluorescence intensity of M1did not change sharply after the coordination of M1with Fe3+in different solution of iron salt with different anions. After coordination of M1with Fe3+, the fluorescence of M1changed just a little under different pH(2-10),which can demonstrate that M1shew a very wide range of application. The result that the process of M1recognizing to Fe3+was reversible was got by the phenomenon that the fluorescence of Ml was recovery when adding Na2EDTA to the system of Ml and Fe3+. In addition, the possible coordination mechanism of M1with Fe3+was studied through the’H-NMR titration experiment of M1which shew that with the addition of Fe3+, Ml combined with Fe3+in two ways by2-pyridine methyl-2-thiophene methyl-amine and triazole amine groups which are the structure of M1and M1coordinated with Fe3at the ratio1:2. In conclusion, M1was an excellent fluorescence probe. |
