Design, Synthesis And Properties Study Of The Near-Infrared Cyanine Dyes

The maximum absorption wavelength and emission wavelength of cyanine near-infrared fluorescent probes range from 650 to 1000 nm.Absorption and emission of organisms and tissues in this range are very weak.Near-infrared cyanine probes have less light damage,deeper tissue penetration,and less background interference to biological samples,so have been applied to various biological analysis technologies,including molecular diagnostics,drug carriers,DNA sequencing,fluorescence immunoassay detection,quantitative determination of biological macromolecules,and in situ fluorescence hybridization techniques,some research results have been applied to actual production and life.However,due to the shortcomings of cyanine dyes such as small Stokes displacement and poor light stability,these disadvantages are investigated.In this article,three series of structures were designed and synthesized.They are mid-nitrogen-substituted heptaacetonitrile dyes,novel cyanine dyes,and novel trimethine-cyanine dyes.Their spectral properties,stability,and cytotoxic fluorescence imaging were studied.Firstly,design and synthesis of meso-position-nitrogen-substituted pH-responsive near-infrared fluorescent probes Cy7-HM,Cy7-ML and Cy7-PM containing diamines using heptamethine cyanine dye as the parent nucleus.In the probe structure,the parent nucleus of heptachlorocin is a near-infrared chromophore,the morpholine ring is a targeting group for cell lysosomes,and the meso-position-substituted diamine structure has a pH response characteristic.The pH response of the probe and the ability to localize lysosomes in HeLa cells were measured.Second,using 2,3,3-trimethyl-3H-anthraquinone and naphthalene ethyl ketone as raw materials,asymmetric novel cyanine dyes Cy-NH,Cy-NQ and Cy-NA with large Stokes shift were designed and synthesized by salt formation and condensation.The absorption and emission spectra of dyes in different polar solvents,stability,cytotoxicity,and localization of lysosomes in Hela cells were determined.