Multifunctional two-photon active silica-coated Au@MnO Janus particles for selective dual functionalization and imaging.
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.
Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität , Duesbergweg 10-14, 55128 Mainz, Germany.
Isabel
I
Schick
Steffen
S
Lorenz
Dominik
D
Gehrig
Anna-Maria
AM
Schilmann
Heiko
H
Bauer
Martin
M
Panthöfer
Karl
K
Fischer
Dennis
D
Strand
Frédéric
F
Laquai
Wolfgang
W
Tremel
D001692:Biological Transport; D045744:Cell Line, Tumor; D002470:Cell Survival; D003952:Diagnostic Imaging; D006046:Gold / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D017785:Photons; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
D006046:Gold; D012822:Silicon Dioxide