Synthesis Of Rhodamine And Its Derivatives And Research Of Their Spectral Properties

In recent years, a lot of techniques used to detect different kinds of analytes inthe environment, medicine and bio-systems have been developed. Fluorescentsensors, because of its high sensitivity, good selectivity, quick response, highspatial and temporal resolution, as well as low cost, has been attached widespreadattention and has been fully developed[1]. So far, many small molecular probes onthe basis of various fluorescent dyes have been developed, however, most of thefluorescent probes of which the absorption and emission wavelength is in thevisible region, which will cause strong background fluorescence, and therefore isnot suitable for the detection of analytes in living cells and tissues. While thefluorescent probes with the absorption and emission peak in near infrared region(NIR)(650-900nm) probe can be a very good solution to this problem. However,there are some defects in the current design of NIR dyes, so it is still a bigchallenge to develop NIR fluorescent probes.In the article’s first chapter, we simply introduced the mechanism offluorescence and some influencing factors of the fluorescence, and then we brieflyintroduced the commonly used fluorescent dyes and their classical methods ofsynthesis.In the second chapter, on the basis of rhodamine6G dye, we designed andsynthesized a new type of probe, which can be used to detect H2S on themechanism of fluorescent “on-off” switch. By analysis of the spectrum data, wefound that the probe response to H2S shows a good selectivity and high sensitivityas well as the obvious color change which can be observed by the naked eye.In the third chapter, we designed and synthesized a series of rhodaminederivatives with the fluorescent wavelength from deep infrared to near infraredregion and the photophysical properties have been studied. Compared to theclassical rhodamine, they not only keep fluorescent switch properties of theclassic rhodamine switch ring properties, but also show a varity of advantages,such as larger stokes shift, the highly stable photophysical properties andabsorption and emission peak in the region from deep infrared to near infrared,indicating that these rhodamine derivatives have great biological value and can beserved as a foundation to develop NIR fluorescent probes.