Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität , Duesbergweg 10-14, 55128 Mainz, Germany.
J Am Chem Soc. 2014 Feb 12;136(6):2473-83. doi: 10.1021/ja410787u. Epub 2014 Feb 4.
Monodisperse multifunctional and nontoxic Au@MnO Janus particles with different sizes and morphologies were prepared by a seed-mediated nucleation and growth technique with precise control over domain sizes, surface functionalization, and dye labeling. The metal oxide domain could be coated selectively with a thin silica layer, leaving the metal domain untouched. In particular, size and morphology of the individual (metal and metal oxide) domains could be controlled by adjustment of the synthetic parameters. The SiO2 coating of the oxide domain allows biomolecule conjugation (e.g., antibodies, proteins) in a single step for converting the photoluminescent and superparamagnetic Janus nanoparticles into multifunctional efficient vehicles for theranostics. The Au@MnO@SiO2 Janus particles were characterized using high-resolution transmission electron microscopy (HR-)TEM, powder X-ray diffraction (PXRD), optical (UV-vis) spectroscopy, confocal laser fluorescence scanning microscopy (CLSM), and dynamic light scattering (DLS). The functionalized nanoparticles were stable in buffer solution or serum, showing no indication of aggregation. Biocompatibility and potential biomedical applications of the Au@MnO@SiO2 Janus particles were assayed by a cell viability analysis by coincubating the Au@MnO@SiO2 Janus particles with Caki 1 and HeLa cells. Time-resolved fluorescence spectroscopy in combination with CLSM revealed the silica-coated Au@MnO@SiO2 Janus particles to be highly two-photon active; no indication for an electronic interaction between the dye molecules incorporated in the silica shell surrounding the MnO domains and the attached Au domains was found; fluorescence quenching was observed when dye molecules were bound directly to the Au domains.
通过种子介导的成核和生长技术，制备了具有不同尺寸和形貌的单分散多功能无毒 Au@MnO 手性粒子，可以精确控制畴尺寸、表面功能化和染料标记。可以选择性地用薄的二氧化硅层包覆金属氧化物畴，而使金属畴不受影响。特别是，通过调整合成参数，可以控制单个（金属和金属氧化物）畴的尺寸和形貌。氧化物畴的 SiO2 涂层允许在一步中进行生物分子缀合（例如，抗体，蛋白质），从而将光致发光和超顺磁 Janus 纳米粒子转化为用于治疗和诊断的多功能高效载体。使用高分辨率透射电子显微镜（HR-TEM）、粉末 X 射线衍射（PXRD）、光学（UV-vis）光谱、共焦激光荧光扫描显微镜（CLSM）和动态光散射（DLS）对 Au@MnO@SiO2 手性粒子进行了表征。功能化纳米粒子在缓冲溶液或血清中稳定，没有聚集的迹象。通过将 Au@MnO@SiO2 手性粒子与 Caki 1 和 HeLa 细胞共孵育，通过细胞活力分析测定了 Au@MnO@SiO2 手性粒子的生物相容性和潜在的生物医学应用。时间分辨荧光光谱结合 CLSM 表明，包覆二氧化硅的 Au@MnO@SiO2 手性粒子具有很高的双光子活性；未发现掺入二氧化硅壳层中的染料分子与附着的 Au 域之间存在电子相互作用的迹象；当染料分子直接与 Au 域结合时，观察到荧光猝灭。
