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

Abstract

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 viaultraviolet-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.