Synthesis And Materialization Of Rhodamine B Fluorescent Probes

In recent years, the contamination of heavy metal ions and the pollution of the atmosphere have been becoming increasingly serious. The industrial production process whose raw material is mercury produces waste water, waste gas and waste residue. These matters not only cause serious pollution to the environment, but also damage the health of people. Nitrogen oxides especially nitric oxide (NO) is one of the major atmospheric pollutants. Nitric oxide is easy to bound with hemoglobin, causing acute chronic, toxicity and hypoxia, thereby affecting and endangering human health. But the research also shows that a small amount of NO has an important physiological role in the human body. It can enhance a person’s memory function. Therefore, the development and research to recorgnize the heavy metal ions and NO have attracted people’s great attentions.Firstly, we synthesized two inorganic-organic hybrid fluorescence chemosensors (SBA-RB1and SBA-RB2), they were prepared by materialization between Rhodamine B derivatives and SBA-15(a kind of mesoporous silica material). UV-Vis, IR, XRD and Nitrogen adsorption-desorption isotherms showed the primary ordered mesoporous structure of SBA-15was not changed after the materialization procedure. Experiments showed both SBA-RB1and SBA-RB2could detect Hg2+sensitively over other competitive cations with a limitation lower to ppb range. SBA-RB1and SBA-RB2have effectively chromogenical and fluorogenical responses when treated with Hg2+in a range of pH5-9. Other experiments showed there was a well linearity function between the fluorescence intensity and the concentration of Hg2+. Besides, both SBA-RB1and SBA-RB2can be recycled in the environmental usage by EDTA. All these suggested the possibility of the two chemosensors for real-time quantitative detection of Hg2+in environmental science.Two Cu2+complexes of rhodamine B, RBNS-Cu and RBNF-Cu, were designed and synthesized. Both the complexes can selectively and sensitively detect NO. Meanwhile other biological species such as NO2-、ONOO-、NO3-、H2O2、ClO-and1O2did not cause any interference. The fluorescence intensity of RBNS-Cu increased45-fold upon addition of NO while the fluorescence intensity of RBNF-Cu increased4-fold. Our reseach showed that it was Cu2+that catalyzed the two ligands hydrolysis and at the same time a diamagnetic Cu+species were produced by the reduction of NO with Cu2+, and the loop structure of rhodamine B was opened, thereby causing the increase of the fluorescence intensity.