Magnetically responsive silica gold nanobowls for targeted delivery and SERS based sensing.
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.
Nanoscale