Composite colloidal structures with multi-functional properties have wide applications in targeted delivery of therapeutics and imaging contrast molecules and high-throughput molecular bio-sensing. We have constructed a multifunctional composite magnetic nanobowl using the bottom-up approach on an asymmetric silica/polystyrene Janus template consisting of a silica shell around a partially exposed polystyrene core. The nanobowl consists of a silica bowl and a gold exterior shell with iron oxide magnetic nanoparticles sandwiched between the silica and gold shells. The nanobowls were characterized by electron microscopy, atomic force microscopy, magnetometry, vis-NIR and FTIR spectroscopy. Magnetically vectored transport of these nanobowls was ascertained by time-lapsed imaging of their flow in fluid through a porous hydrogel under a defined magnetic field. These magnetically-responsive nanobowls show distinct surface enhanced Raman spectroscopy (SERS) imaging capability. The PEGylated magnetically-responsive nanobowls show size-dependent cellular uptake in vitro.
Bibliographical noteFunding Information:
We would like to thank Professor Jan Talbot for access to the DLS instrument. We thank the NANO3 staff for access to the SEM and related support. We thank Issac Liu and Professor Sungho Jin for access to the VSM. Also thanks to UCSD Electron Microscope Facility staff Timothy Meerloo and Ying Jones for access to the TEM and related support. Thanks to Matthew Rozin for help with the UV-vis-IR spectrometer. Finally thanks to Professor Seth Cohen for access to the FTIR instrument. This work was funded by UCSD startup funds and NIH grants R01DA024871 and R01DA025296 to R. L. Post-doctoral Fellowship (237085) provided by Consejo Nacional de Ciencia y Tecnolo?a (CONACyT) to K. S.-G.
© 2016 The Royal Society of Chemistry.