The Synthesis And Application Of Fluorescent Sensor For Se (Ⅳ) Based On Rhodamine6G

Selenium (Se) is an important metalloid with industrial, medical, nutrition,environmental, biological, and toxicological significance. It is recognized as a nutrientelement essential to most mammalian species. Se participates actively in proteinsynthesis. About50proteins in bacteria, archaea, and mammals contain Se. Themetalloid fulfills important roles in anticarcinogenic activity and protection againstthe toxic effects of heavy metals. However, the concentrations of selenium onlybetween a narrow range (70to100μg/day) is beneficial to health. Beyond this range,Se deficiency or poisoning can cause diseases. Hence, the accurate determination ofmicro or trace amounts of Se is of great importance.Se exists in both inorganic and organic forms. Inorganic Se species are more toxicthan organic ones. Many techniques for the determination of selenium have beenreported over the years with higher sensitivity and lower detection limit. Nevertheless,the drawbacks of these methods are fairly obvious. For example, the interference ofother metals, complex operation, the high price and maintenance costs of theanalytical equipment and harsh experimental conditions and so on. In recent years,energies are dedicated to design various selective chemosensors. Fluorescent sensorsare very attractive because they are highly efficient for discriminating target analytesover the inherent spectrally complex background in real-world samples. In this paper,we reported the development of a new fluorescent probe with highly sensitivity andselectivity for the determination of Se (IV).Chapter One provided an overview of selenium, introduced the importance ofdetection Se (IV), detection methods and made a brief review on fluorescent probes todetect Se (IV).In chapter two, an inducible fluorescent ligand2-(2-(2-aminoethylamino)ethyl)-3’,6’-bis(ethylamino)-2’,7’-dimethylspiro[isoindoline-1,9’-xanthen]-3-one(ABDO) wassynthesized and used as a fluorescent probe to detect Se (IV).. Its structure has been characterized by NMR and MS. we studied the properties of the Selenium fluorescentsensor and the complex mechanism of Se (IV) and ABDO. The sensor shows greatselectivity and sensitivity for Se (IV) determination. Upon coordination with Se (IV),the chemosensor showed incredible fluorescence enhancement, other metal ions andanions had no significant interference on Se (IV) determination. The chemosensorexhibits a dynamic response range for Se (IV) from10nmol/L to3μmol/L, with adetection limit of2.8×10-9mol/L. The selenium content of multivitamin tablets canbe detected quickly and efficiently by fluorescence method.In chapter three, the chemosensor we synthesized was applied successfully toHela cell imaging. Finally, we made a summary and prospect on the chemosensor forits application on correlative study.