Design And Synthesis Of Multifunctional Modified Rylene Imides Fluorescent Probe And Targeted Organelle Imaging

As a new analytical detection technology,fluorescent molecular imaging needs high-performance fluorescent molecular probes.Rylene imides dyes are a kind of fluorescent dyes with excellent properties because of their high luminous brightness and good photochemical stability.However,due to poor cell compatibility and lack of targeted dyeing ability,Rylene imides dyes lag far behind other dyes in the application of biofluorescence imaging.In this paper,Rylene imides dyes are functionally modified to regulate the luminous color of dyes,improve their cell membrane permeability and target organelle dyeing ability,and provide high-performance fluorescent molecular probes for biological fluorescence imaging.The specific research contents are as follows:1.Azetidines modified naphthalimide fluorescent probe and lipid droplet targeted imagingA series of azetidines were connected to naphthalimide.A new multifunctional substituted naphthalimide（MFGNI）dye was designed and synthesized,and their optical properties were studied.MFGNI dye is emitted in dichloromethane solutionλ_em ranges from444 nm to 511 nm,and has high fluorescence quantum yield and large Stokes shift.These MFGNI dyes specifically stain lipid droplets and show excellent photostability in living cells.High brightness,large Stokes shift,light stability and specificity make these MFGNI dyes promising as new probes for lipid droplet imaging.2.Azetidines modified perylene diimide（AZPDI）fluorescent probe and lipid droplet targeted imagingNovel multifunctional substituted perylene diimide AZPDI dyes were designed and synthesized,and their optical properties and living cell imaging were studied.Fluorescence emission of AZPDI series dyes in dichloromethaneλ_em ranges from 590 nm to 732 nm and has high fluorescence quantum yield（from 38%to 95%）and large Stokes shift（from 35 nm to 110 nm）.These AZPDI dyes specifically stain lipid droplets,with a high Pearson co localization coefficient between（0.91-0.98）and excellent photostability in living cells.High brightness,large Stokes shift,light stability and specificity make these AZPDI dyes become new fluorescent probes for lipid droplet imaging.3.Isopropylphenyl groups encapsulate perylene diimide fluorescent probe and lipid droplet targeted imagingA multifunctional group modified PDIs dye SFPDIs was designed and synthesized by introducing isopropyl benzene sulfone group into the molecular chain of PDIs.The introduction of hydrophilic sulfone group in the bay of perylene imide can inhibit molecular aggregation and fluorescence quenching,improve the fluorescence quantum yield（93%）,and give the dye good cell membrane permeability.Lipophilic isopropyl phenyl endows the probe with good lipid droplet targeting staining ability in living cells.SFPDIs shows high antioxidant capacity in living cell lipid droplet imaging.It is a kind of cell lipid droplet imaging probe with excellent performance.4.Functional modification of perylene diimide fluorescent near infrared dye and targeted mitochondrial/lysosomal imagingMito PDI and Lyso PDI were synthesized by introducing mitochondrial and lysosomal recognition groups into AZPDI functional dyes,respectively.Their luminescence is in the near-infrared region（719 nm and 707 nm）,with high fluorescence quantum yield（49%and48%）and large Stokes shift（109 nm and 98 nm）.Mito PDI and Lyso PDI dyes have good staining ability of living cell mitochondria and lysosomes,respectively.Using the large Stokes shift and near-infrared luminescence characteristics of Mito PDI and Lyso PDI,we incubated lipid droplet dye PDIs-536 with Mito PDI and Lyso PDI in He La cells respectively.Using single wavelength excitation dual channel synchronous imaging,we clearly observed the distribution of each organelle,and successfully realized the simultaneous imaging of the two organelles.In short,we designed and synthesized a series of new functional dyes by functional modification of rylene imide dyes.These new rylene imide functional dyes cover blue,green,orange,red and near-infrared regions.They have high luminous efficiency,large Stokes shift,good stability and organelle targeted dyeing ability.They are a kind of fluorescent molecular probes with good application prospects in the field of biological fluorescence imaging.