Synthesis Of NaYF₄:Yb,Er@NaYF₄:Yb Nanoparticles And Its Loads Of Photosensitizer And Anticancer Drug

Up-conversion luminescence nanomaterial was a kind of anti-Stokes luminescence materials,which could emit high-energy shorter wavelength light being excited by long wavelength light.Nowadays,rare earth up-conversion nanoparticles have been used in many biochemical fields,such as photodynamic therapy,drug delivery,biological detection,biological imaging and so on,due to their characteristic high luminous intensity,narrow emission bands,good optical stability,luminous long life,deep tissue penetration,low potential cytotoxicity,minimal background interference.In this paper,NaYF4:Yb,Er@NaYF4:Yb up-conversion nanoparticles were synthesized and their was used in the study of drug loading.NaYF4:Yb,Er@NaYF4:Yb nanoparticles were synthesized by solvothermal method with water-ethanol-oleic as the solvent and rare earth stearate as the precursor.The synthesis conditions were optimized based on the luminescence intensity of UCNPs.Compared with NaYF4:Yb,Er nanoparticles,the luminescence intensity of NaYF4:Yb,Er@NaYF4:Yb nanoparticles synthesized at the optimal conditions was increased by 2.37 times.The nanoparticles were characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),infrared spectrometer(IR)and laser fineness gage.The results showed that the particles were spherical with the size of 40?60 nm and they were hexagonal and cubic crystals,the nanoparticles coated with the oleic acid on the surface.In addition,the average diameter was determined to be 41 and 54 nm for NaYF4:Yb,Er core-only and NaYF4:Yb,Er@NaYF4:Yb core-shell nanoparticles,respectively,indicating the thickness of NaYF4:Yb shell was about 7 nm.In order to use the synthesized nanoparticles for drug loading,UCNPs were coated with mesoporous silica shell.The synthesis conditions were optimized based on the loading capacity of methyl orange on UCNPs@mSiO2.The as-prepared UCNPs@mSiO2 were characterized by many methods.FT-IR demonstrated the particles were coated with silica shell,mesoporous silica shell was deposited onto the surface of UCNPs when the template CTAB was completely removed.N2 adsorption-desorption isotherms showed that the BET surface area of UCNPs@mSiO2 was about 330 m2/g,and the average pore size was 3.13 nm.Chlorin e6(Ce6),a photosensitizer agents,was loaded with synthesized UCNPs@mSiO2,and its saturated loading capacity was 9.5%(w/w).Herein,1,3-diphenylisobenzofuran(DPBF)was used as an indicator to investigate 1O2 produced by UCNPs@mSiO2 under the excitation of near-infrared.Doxorubicin(DOX),a anti-cancer drug,was loaded with synthesized UCNPs@mSiO2,and its saturated loading capacity was 8.9%(w/w).All of these indicated that the synthesized nanoparticles had a good loading capacity.