Design And Application Of The BODIPY-based Fluorescent Probes For Copper

Copper is an essential element for living systems. Although the content of copper is very small in human body, it is of great importance to maintain and regulate the normal metabolism of the whole system. If the metabolism of copper is unnormal, a series of diseases may be triggered such as Alzheimer’s disease, prion disease, Parkinson’s disease, amyotrophic lateral sclerosis, Menkes disease, and Wilson’s disease. When the content of copper is too high, it will have enormous toxic effects and harm to human health seriously. Because of the importance of copper, the distribution of copper in living systems should be controlled strictly. Therefore the detection of copper is of great significance.In recent years, various detection methods progresses rapidly, of which fluorescence detection method is particularly excellent. The advantages of fluorescent sensors are high sensitivity, high specificity, besides the method is simple, quick and easy, and it can be achieved in situ, real-time monitoring. The boron dipyrromethene dyes (difluoro-bora-dipyrromethenes, BODIPY) have many excellent photophysical and chemical properties, such as high photostability, high fluorescence quantum yields. Moreover, the dyes have less susceptible to pH and solvents in fluorescence detection. And in the absorption and emission spectra, relative peaks are really narrow in visible region. The dyes can be modified to near-infrared region for further biological application.Based on the design pattern of reaction fluorescent sensors, the basic principles of molecular recognition, we designed and synthesized series of of BODIPY fluorescent dyes. With the introduction of recognition sites, the sensors can be used for fluorescence imaging applications in living cells. Three fluorescent sensors, BBCu, BFCu, and BTCu were synthesized. The three Cu2+fluorescent sensors are based on fluorescence enhancement, and they only contain different ligand structures in the recognition sites. The identification effect of BTCu is the best in the three, and recognition mechanism of Cu2+has been further confirmed. Also a Cu2+ratiometric fluorescent sensor BBM was designed and synthesized. In organic solvent, the sensor not only achieved red-shift in emission spectra, but also showed a good response to Cr3+, which did not affect the identification of Cu2+.