Study Of The Rhodamine-based Fluorescent Probes For Copper And Gold

In recent years, the fluorescence analysis method has become polular due to it’s simpleness, high sensitivity, good selectivity, speediness and easiness. The rhodamine dyes show excellent photochemical and photophysical properties, including high molar extinction coefficient, high fluorescence quantum yields, high photo stability and good cell membrane permeability. The unique spirolactam-ring opening system of rhodamin derivative provides an ideal platform for the design and synthesis of fluorescent probes.Copper is an important transitional metal element for human body, and the content of copper inside is too high or too low both will cause enormous toxic effects to human health. The internal copper come from river and food, therefore the detection of copper in the environment is of great significance. We have designed and synthesized a fluorescence probe SRR for Cu2+. Due to the strong binding ability of tridentate S receptor towards Cu2+, SRR shows a single-selectively sensing Cu2+over other cations. The detection limit is as sensitive as10nM meanwhile the sensing process could complete within3min. Moreover, the present probe can be made into test paper to detect Cu2+. The detection mechanism was investigated by TOF-MS,13C-NMR,31P-NMR,1H-NMR, ESR and Gaussian calculations. And a coordination of Cu2+with the tridentate S receptor, promoting ring-opening of rhodamine, followed by a redution reaction (Cu2+to Cu+) were proprosed for the sensing process.Gold has been widely used in chemistry and pharmaceutical science. However, soluble gold salts are known to cause damage to the body and the accumulation of gold species in the body will lead to serious toxicity to humans. Thus, it is highly desirable to develop fluorescent probes for monitoring of Au3+in environment and living system. We have developed an enhanced fluorescent probe RY for Au3+based on rhodamine. The probe was easily synthesized with high yield. Probe RY was selective for Au3+detection, and showed high sensitivity to Au3+with detection limit of36ppb. Furthermore, it could be successful used to fluorescence image in both living cells and mice. It’s of potential value for the study of gold ion’s biological activity and toxicity in living organisms.