Construction Of Nanomatryoshkas Gold Nanorods-Thio-Azo Substituted Silicon Phthalocyanine Naonoconjugates And Their Two Photo Fluorescence Enhancement Effect

It is difficult to achieve deep tissue treatment and activate specifically,and to realize the diagnostic integration of photodynamic therapy and photothermal therapy.In this paper,a series of nanomatryoshkas gold nanorods-thio-azo substituted phthalocyanine naono conjugates were constructed,and their two-photon fluorescence enhancement effect and the antibacterial effect were studied.A novel series of axially substituted silicon(?)phthalocyanine with thio-azo heterocycles substitution were synthesized.They were bis-(1-(4-hydroxy-phenyl)-5-mercapto-tetrazolium)silicon(?)phthalocyanine(Tet-SiPc),bis-((R)-N-(4-hydroxyphenethyl)-1-((S)-3-mercapto-2-methylpropanoyl)pyrrolidine-2-car boxamide)silicon(?)phthalocyanine(Ace-SiPc)and bis-(N-(4-hydroxyphenethyl)thiophene-2-carboxamide)silicon(?)phthalocyanine(Thi-SiPc).The structures of these silicon(?)phthalocyanines were characterized by FT-IR,Raman spectra,1H NMR,and ESI-MS methods.The photophysical properties of these phthalocynianes were studied by UV/Vis,steady-state and time-resolved fluorescence spectroscopic analyses.The effects of the properties of functional groups and chain length on UV/Vis,steady-state fluorescence spectra,fluorescence lifetime and fluorescence quantum yield of axially substituted silicon(IV)phthalocyanine were compared.The singlet oxygen production ability of these thio-azo heterocycles axially substituted silicon(?)phthalocyanine complexes were compared.It was found that Tet-SiPc exhibited the highest fluorescence intensity and fluorescence lifetime,while Ace-SiPc had strongest singlet oxygen production ability.The nanomatryoshkas gold nanorods(AuNR@SiO2-NH2@Au)with cavity structure were prepared by layer-by-layer growth method,Gold nanorods were synthesized by seed growth method.AuNR@ SiO2-NH2 was prepared by coating mesoporous silica layer on the surface of AuNR with a hydrolysis method.Finally,a layer of gold nanoparticles was coated by seed growth method.The morphologies of a series of nanomatryoshkas gold nanorods were characterized by TEM,AFM,DLS and Zeta potential.The results showed that Tet-SiPc were assembled on the hollow SiO2-NH2 layer of AuNR@SiO2-NH2@Au or suface of out-layer gold nanoparticle by adsorption and Au-S bonds to obtain nanomatryoshkasus Tet-SiPc@AuNR(@SiO2-NH2@Au nanocomposite system.The sutructure of Tet-SiPc@AuNR@SiO2-NH2@Au were charaterized by TEM and EDS.The photophysical properties and photostability of Tet-SiPc@AuNR@SiO2-NH2 @Au system were studied by UV-Vis absorption and two-photon laser fluorescence spectroscopy.The photothermal conversion efficiency and the singlet oxgen production ability were studied,.The photoactivation control Tet-SiPc release kinetics curve was ploted.With the increase in the number of layers of nanomatryoshkasus gold nanorod system,the amount of Tet-SiPc increased,a markable redshift of maximum absorption peak of AuNR @SiO2-NH2@Au,and the enhance two-photon excited fluorescence(TPL)were observed;Tet-SiPc could enhance the TPL of AuNR @SiO2-NH2@Au,and the photothermal conversion efficiency,as well as the singlet oxygen generation ability.Tet-SiPc@AuNR@SiO2-NH2 @Au could photoinactivated E.coli and the efficacy reached 90%.The photophysical and photochemical properties of nanomatryoshkas gold nanorods nanoparticles loaded with different thio-azo heterocycles substituted silicon phthalocyanines(Ace-SiPc and Thi-SiPc)were compared.Its two-photon fluorescence enhancement effect exhibited the properties of phthalocyanine dependences.Compared with Thi-SiPc,the amount of Ace-SiPc loaded in different layers of gold nanorods composite nanoparticles increased,and two-photon fluorescence intensity enhanced,and singlet oxygen generation ability also increased.