以泊洛沙姆(F-127)为模板剂,以硅氧烷化芘的衍生物 4-(1-芘基)-N-[3-(三乙氧基硅基)丙基]丁酰胺(Pyrene-1)与正硅酸四乙酯(TEOS)的混合物为硅源,通过胶束模板法制备了Pyrene-1掺杂的SiO2荧光纳米粒子.采用透射电子显微镜(TEM)、动态光散射仪(DLS)、紫外-可见分光光度计和荧光光谱仪等对Pyrene-1掺杂的SiO2荧光纳米粒子的表观形貌、粒径分布和光物理性质进行了表征.结果表明,所制备Pyrene-1掺杂的SiO2荧光纳米粒子粒径均一(TEM统计粒径约为12 nm, DLS表征的水合直径约为33 nm),在水中具有很好的分散稳定性.通过调节染料的掺杂比例可以有效调控染料分子间距.同时,由于染料分子被共价键固定在Si—O—Si骨架中,使Pyrene-1掺杂的SiO2荧光纳米粒子的荧光量子效率大幅提高(从有机溶剂中的0.15提升至0.95),荧光寿命得以延长(从有机溶剂中的17.9 ns延长至191.8 ns).在染料掺杂比例较高时,通过生成激基缔合物(Excimer),形成了具有较大Stokes位移(~100 nm)的发光.%Pyrene-doped silica fluorescent nanoparticles were prepared based on the micelle-template method. In the system, pluronic(F-127)was employed as template reagent, the mixture of pyrene trialkoxysilane derivatives(Pyrene-1)and tetraethoxysilane(TEOS)was used as silica precursors. The morphology, size distribution and photophysical properties of the obtained nanoparticles were characterized by means of transmis-sion electron microscopy(TEM),dynamic light scattering(DLS), UV-Visible spectrophotometer and fluores-cence spectrophotometer. The diameter of the nanoparticle measured by TEM was about 12 nm and the hydro-dynamic diameter measured by DLS was about 33 nm. The prepared nanoparticles with uniform size showed good dispersibility and stability in water. The distance between dye molecules could be adjusted by changing the molar ratio between Pyrene-1 and TEOS. In addition, the dyes were fixed by the covalent bonds with Si—O—Si backbone in the nanoparticles,resulting in the increasing of fluorescence quantum yield(from 0.15 to 0.95 in CHCl3)and monomer fluorescence lifetime(from 17.9 ns to 191.8 ns in CHCl3). For the nanopar-ticles with high concentration of Pyrene-1,distinct Stokes shift up to 100 nm could be observed owing to the generation of excimer of Pyrene-1 molecules.
展开▼
