Research Project

Synthesis of Vertically-Aligned Gold Nanowires Embedded in Ferromagnetic Matrices

Commercial chips are used to detect and identify chemical and biological agents and explosive compounds at trace level. Our goal in this work is to generate large area, reproducible, and homogeneous LSPR substrates that improve detection limits for biological and chemical sensors to ultra-trace level.

Nanostructured materials have attracted our interests for their unique electrical and optical properties for localized surface plasmon resonance (LSPR) substrates. LSPR describes a resonance phenomenon of surface electron density in metallic nanoscale structures when the size of materials is less than the wavelength of an incident light. Commercial chips, such as portable Raman systems, are used to detect and identify chemical and biological agents and explosive compounds at trace level. Our goal in this work is to generate large area, reproducible, and homogeneous LSPR substrates that improve detection limits for biological and chemical sensors to ultra-trace level.

LSPR signaling enhancement depends on the size, shape, and interspacing of nanostructured materials. Highly ordered nanowire arrays can sustain large electromagnetic fields at a high density of sites within the structure upon the excitation of light. This structure can give us an excellent substrate for LSPR enhancement.

In addition to that, we proposed the idea that the extra magnetic field component from the ferromagnetic matrices in the fabricated Au (elemental gold) nanowire ferromagnetic composites would act as an addition to the plasmonic field, thus amplifying the LSPR response.

The synthesis of Au nanowires embedded in ferromagnetic (Ni and Fe) matrices involves first electrodepositing the Au nanowire arrays within anodic aluminum oxide (AAO) nanoporous membranes. After dissolving the membranes, the ferromagnetic matrices are evaporated and electrodeposited around the nanowires to produce the two-phase nanocomposites.

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