Au@ZIF-8核壳结构中金纳米粒子分布的调控及其在荧光分子光致发光传感中的应用

控制金属@MOF核壳纳米结构中金属纳米粒子的分布不容易实现。我们应用了合成MOF胶体粒子所用到的配位调制方法来合成Au@ZIF-8核壳纳米结构。通过使用过量的2-甲基咪唑和不同用量的1-甲基咪唑可获得不同的Au@ZIF-8。该合成方法可在ZIF-8纳米晶体中灵活调整Au纳米粒子（Au NPs）的分布。此外，我们分别研究了2种不同尺寸的荧光分子与Au@ZIF-8结合后的光致发光光谱和寿命。ZIF-8的孔径可以决定这2种分子是否可通过多孔壳结构接近Au NPs。分子光学特性对Au NPs近场的发光增强和荧光猝灭的竞争非常敏感。

Controlling Distribution of Gold Nanoparticles in Au@ZIF-8 Core-Shell Structures for Sensing Fluorescent Molecules with Photoluminescence

Controlling the distribution of metal nanoparticles in metal@MOF core-shell structures is not easy to realize. We applied the coordination modulation method which has been studied in the synthesis of MOF colloids to synthesize Au@ZIF-8 core-shell nanostructures. Different Au@ZIF-8 core-shell nanostructures have been achieved by employing an excess amount of 2-methylimidazole and various amount of 1-methylimidazole. With our method, the distribution of Au nanoparticles (Au NPs) could be flexibly tuned in the ZIF-8 nanocrystals. Moreover, we investigated the photoluminescent spectra and lifetime of two fluorescent molecules with different sizes, combined with Au@ZIF-8 separately. The aperture size of ZIF-8 determines whether to let the molecules pass through the porous shell to approach Au NPs, and the molecular optical properties are sensitive to the competition of luminescent enhancement and fluorescent quenching of Au NPs.