Synthesis And Application Of Novel Rhodamine Fluorescent Dyes

Due to the high penetrability and low phototoxicity of near-infrared light and the low self-fluorescence background of biomolecules in the near-infrared region,near-infrared fluorescent dyes are the preferred fluorescent dyes in the field of bioluminescent sensing currently.However,most commercial near-infrared fluorescent dyes have low fluorescence quantum yield,poor light stability,and emission wavelength lower than 800 nm.In practical applications,they are limitations of low sensitivity,easy photobleaching,and weak light penetration.Therefore,the development of near-infrared fluorescent dyes with excellent photophysical properties is one of the research topics of current chemists.In the first chapter,the authors systematically reviewed the common near infrared fluorescent dyes,including cyanine,BODIPY,rhodamine and their corresponding derivatives,and gave examples of their applications in biology.In the second chapter,due to the cumbersome synthesis and not conducive to the quantitative preparation of the traditional “carbon-rhodamine” dye,we have developed a new method for synthesizing "carbon-rhodamine" dyes from commercial cheap ketones and synthesized a series of new near-infrared "carbon-rhodamine" fluorescent dyes CRs,and its photophysical properties were evaluated.These dyes have good water solubility,high chemical stability,good light stability,and biocompatibility.In addition,compared with the traditional “carbon-rhodamine” dyes,the series “Carbon-Rhodamine” synthesized in the paper not only retains its high quantum yield characteristics,but also the emission wavelength is further redshifted to more than 650 nm.,selective fluorescence imaging of cell mitochondria can be achieved by laser confocal fluorescence microscopy.In the third chapter,a series of novel "carbonyl-rhodamine" fluorescent dyes CBR were synthesized by substituting the monoatomic modification of traditional rhodamine dyes with a carbonyl group to replace the rhodamine 10 oxygen bridge atom.And spectral properties were characterized.Compared with the traditional rhodamine dye,the absorption and emission wavelengths of the "carbonyl-rhodamine" dye are greatly red-shifted.The emission wavelength is 930 nm,which is close to the near-infrared two-zone window(1000-1700 nm).This kind of "carbonyl-rhodamine" dye has potential research value in the development of near-infrared fluorescent probes and biological imaging research.