Design,Synthesis And Applications Of The Small-molecule Organic Fluorescent Probes

Fluorescent chemosensor grounded on its good selectivity, high sensitivity, the advantages of simple operation to become an active research field in today’s chemistry course, it is a good way to detect the related substances in environmental and biological systems, such as the heavy metal ions, anions in the environment or organism and the application of DNA and other fields has made great progress. There are different kinds of recognition mechanism of the fluorescent chemical sensors. In recent years, There are many reports about the ion sensor, some of them use the fluorescent sensors by an irreversible chemical reaction to produce the change of the fluorescence intensity to analysis ion; Some of them are using fluorescent sensor as a complexation with metal ions to test for a reversible displacement reaction, through the fluorescence signal analysis to achieve the result of testing. This paper synthesized a kind of new fluorescent probe to analysis sulfur and a copper ions fluorescent probe, and we use the the methods of UV spectrophotometry and fluorescence to detect its optical properties as well as to the ability to identify the ion and its mechanism were studied. Chapters content summarized as follows:Chapter1, introduction. This chapter mainly introduces the design principle of fluorescent chemical sensor, classification and the research progress of all kinds of fluorescent chemical sensor.Chapter2, A regeneratable and highly selective fluorescent probe for sulfide detection in aqueous solution In this chapter A novel fluorescent probe based on coumarin-dipicolylamine-Cu2+complex was synthesized and characterized. The probe is able highly sensitive and selective to sense sulfide over other common anionic analytes including thiols followed by releasing ligand1to give a remarkable change of fluorescent intensity in aqueous solution. The probe could be regenerated by addition of Cu2+, and therefore the probe could be utilized repeatly to sense sulfide anions with Cu2+and S2-, in turn, increased. The detection limit of the fluorescent assay for sulfide is as low as14nM with a rapid response time (a few seconds). Importantly, the displacement mechanism for sensing of sulfide anions was clarified through single-crystal X-ray diffraction analysis and DFT calculations. Based on this probe, a rapid, selective and sensitive fluorescence method for the detection of sulfide anions in environmental samples was established.Chapter3, A new fluorescence chemosensor for copper ions. In this chapter we synthesized a new kind of copper ion fluorescent chemical sensors. The probe is used to assist the oxidation of copper ions to the oxidation state, and the enhanced fluorescence occurs at the same time. The probe can be under physiological conditions to dectect copper ions in the environment of the pH value of the good selectivity and the solution color change from colorless to the orange that the naked eye can identified.