Construction Of Nanocrystalline-functional Substituted Phthalocyanine Nanocomposite With Continuous Energy Transfer Sensitization Properties And Their Fluorescence Imaging

In order to overcome the low emission efficiency,poor stability after biological functionalization,and low yield of singlet oxygen in photodynamic therapy of up-conversion nanoparticles,an up-conversion nanocrystal phthalocyanine nanocomposite with continuous energy transfer sensitization were synthesized.The Photophysical and photochemical properties,and cell imaging of nanoconjugates were studied.The paper included the following aspects:(1)synthesis of a series of heterocyclic and fluorinate substitution-silicon(?)phthalocyanine,namely di-(4-trifluoromethylpyrimidine-2-oxy)-substituted silicon(?)phthalocyanine(CF3-SiPc),di-(2-methyl-5-1-imidazolium oxy)-substituted silicon(?)phthalocyanine(MT-SiPc),di-[6-(4-trnfluoromethyl)benzopyran keto-phenoxy silicon(IV)phthalocyanine(M,SiPc),di-[7-(4-trifluoromethyl)benzopyrone-phenoxy]silicon(IV)phthalocyanine(M2SiPc),tetra-[6-(4-trifluoromethyl)benzopyrone-phenoxy]zinc(II)phthalocyanine(M1ZnPc),tetrakis[7-(4-trifluoromethyl)benzopyrone The structures of these phthalocyanines were characterized by 'H NMR,IR and ESI-MS.Their photophysical and photochemical properties were characterized by UV-Vis,fluorescence spectroscopic methods.(2)The lanthanide metal ions-doped nanocrystals NaYF4:Er3+,Yb3+ were prepared by high-temperature hot decomposition method,and the surface of the nanocrystals was modified by positively charged ethylene tetrafluoroethylene nitronium ion.At last,AlPcS4@NaYF4:Er3+,Yb3+ nanocompostion system was electrostatic self-assembled by between negative aluminum phthalocyanine(AIPCS4)and positive upconverted nanocrystals.The morphologies of both AlPcS4@NaYF4:Er3+,Yb3+ and NaYF4:Er3+,Yb3+were studied by TEM,SEM and XRD methods.Upon excitation at 980 nm,the composite undergo continuous fluorescence energy transfer,i.e.,NaYF4:Er3+,Yb3+ continuously excites AIPcS4 at 651 nm,emitting fluorescence at 690 nm,meanwhile simultaneously activates the phthalocyanine to generate singlet oxygen.AlPcS4@NaYF4:Era+,Yb3+ nanocrystals could enter Hela cells through folic acid mediated.(3)A novel nanoparticle loaded with fluorocoumarin-substituted silicon phthalocyanine/upconversion nanocrystals using amphiphilic block copolymer polyethylene glycol monomethyl ether-polycaprolactone(MPEG-PCL)as carrier were prepared by cosolvent method.This water soluble polymeric nanoparticles were spherical nanoparticles with particle size 30 nm,and hydrodynamic diameter about 165 nm.At the same time,the ability of continuous fluorescence energy transfer to activate phthalocyanine and generate singlet oxygen exhibited the nature of fluorocoumarin substituted silicon phthalocyanine substituents.The polymeric nanoparticles improves the energy transfer efficiency between the up-conversion and phthalocyanine which is an effective method for increasing the yield of singlet oxygen.It also provides a new method for the loading of the lipophilic photosensitizer on the inorganic nanoparticles.