The Rhodamine Derivatives Fluorescent Probes Of Synthesis And Detection Of Fe³⁺ And Au³⁺

In recent years, the rapid development of industry to the life brings great benefits but also caused irreversible damage to the environment, especially the domestic pollution of soil and water has reached a very serious degree.Metal ion pollution has become one of the main pollution in environment pollution, these metal ions often play an important and functional role in biology,medicine,chemical science and ecology.The content of iron in the earth is at the second place, less than the content of aluminum. It is also the necessary trace element in biological organisms. It is related with various physiological activities. For examples enzymes catalytic reactions, the process some RNA and DNA syntheses and the respiration.Therefore,detecting the iron ions in the organisms is always a significant research topic. The gold is the rare precious metal element in the environment. It is widely used in various fields because of its important role.In chemical field, the gold ion is used as a gentle and efficient catalyst in the acetylene bond reactions. However,gold is a kind of high toxicity heavy metal ion. With the combination of DNA and nervous systems, the gold ions can lead to the breakage of DNA and the destroy of the nervous systems.In this case, the real-time detection of environment and the biological organism of gold ions is very important. That is to say,a rapid and sensitive detection for environment and biology is important and significant.At present,the conventional methods of metal ion detection include atomic absorption and emission spectroscopy and ion selective electrode method, traditional indicator, etc.These methods need complex units and pretreatment.The big detected consumption,high cost,bad selectivity and sensitivity also make these methods not convenient.Whereas,the metal ion fluorescent probe have not only the advantages of strong specificity and high selectivity,but also can realize the cell situ and imaging analysis.Therefore,the fluorescent probes have crucial status and potential widely applied value in the research of modern science and medicine field(clinical diagnosis, biological technology, molecular biology, materials science,analysis and environmental chemistry, etc).In this paper, we used the gold ion fluorescent probe as a research method and make use of the Rhodamine B lactonic ring unique “open-close”structure to design RH-Fe and RH-Aumetal probes based on Rhodamine B. By 1 H NMR, 13 CNMR and MS had been used to characterize the structure of probe compounds. On the basis of this, we use ultraviolet-visible absorption spectra and fluorescence spectrum methods to investigate the recognition performance of metal ions. We draw these conclusions:1. According to the carbon and nitrogen unsaturated double bond of Schiff base,the nitrogen atom has the property to form the stable complexion with metal, so we designed and synthesized the double Schiff base fluorescent probe RH-Fe.With 30 % acetonitrile water system, we added the Fe3+ in the solution of probe, then we found the color of the solution changed from light yellow to red,the fluorescence intensity and ultraviolet absorption of RH-Fe strengthened with the concentration of Fe3+increasing. The Job’s curve indicated that RH-Fe and Fe3+ can complex with the ratio of 1:1. In the range of pH 5.54-10.12, acid-base property for detecting Fe3+ almost had no interference and its detection limitation is 0.27 μM.So this probe realized the high sensitive and good specifity visual detection.2. Making use of catalytic terminal alkyne and carbonyl cyclization reactions, we designed and synthesized the ratio probe RH-Au. Without Au3+, RH-Au had a high emission at the wavelength of 525 nm. By adding the Au3+after 35 min, the emission intensity was reduced at 525 nm, and it was significantly increased at 592 nm.In the range of pH 6.0-7.4,the acid-base property had no interference with Au3+ and its detect limitation is 0.023 μM. It realized the special detection. Through mass spectrometry and nuclear magnetic titration, the reaction mechanism was proved and produced filter containing probe to detect the 0.78 mM Au3+. As the extension of the theory, RH-Au realized the cell image in A549, It is indicated that RH-Au had the potential applied value in biological living cells.