Ni-Au core-shell nanowires: Synthesis, microstructures, biofunctionalization, and the toxicological effects on pancreatic cancer cells

The nickel (Ni)-gold (Au) core-shell nanowires (CSNWs) were synthesized by a combination of electrodeposition and electroless-plating methods. This template based, electroless-plating approach can control the size and shape of nanostructures by adjusting the experimental conditions. The X-ray diffraction, transmission electron microscopy (TEM), and TEM line-scanning and elemental mapping analyses were applied to investigate the formation and microstructure of the core-shell nanostructure. Also using a focused ion beam lift-out technique provides an important route to prove the inner microstructural details of the CSNWs. The optical characterization showed the surface plasmon absorption shifting with electroless-plating time, whereas the magnetic measurements revealed the shape anisotropy and soft ferromagnetic properties of the NWs. Using the strong interaction between biotin and streptavidin, streptavidin-fluorescent dyes were successfully conjugated on the biotinylated CSNWs. This was then analyzed for the surface plasmon resonance effect and Stokes' shifting via ultraviolet-visible and photoluminescence spectroscopy measurements and imaged by confocal scanning laser microscopy. Proliferating cancer cells (Panc-1) have been used to study the toxicological effects of both Ni-Au CSNWs and Ni NWs in a living cell system: the cellular responses to nanowire effects were observed. Ni-Au CSNWs appeared to be tolerated more by this cell line at the dose tested than Ni NWs.