One-Pot Synthesis of Magnetoplasmonic Au@FexOy Nanowires: Bioinspired Bouligand Chiral Stack

One-dimensional hybrid nanostructures com-posed of a plasmonic gold nanowire core covered by a shellof magnetic oxide nanoparticles (Au@FexOyNWs) weresynthesized by a one-pot solvothermal synthesis process. Theeffects of reaction temperature, time, reducing agent, andprecursor as well as postsynthesis treatment were optimized toproduce highly uniform NWs with a diameter of 226 +/- 25 nmand a plasmonic core aspect ratio of 25 to 82. By exploiting theinteraction of NWs with an external magneticfield, precisearrangements into highly periodic photonic structures wereachieved, which can generate distinctive structural colors thatare vividly iridescent and polarization-sensitive. Furthermore, aBouligand-type chiral nematicfilm consisting of multistackedunidirectional layers of achiral NWs was fabricated using a modified layer-by-layer deposition method, which displays circulardichroism (CD) and chiral sensing capability. The addition of bovine serum albumin (BSA) as a model protein analyteinduced a concentration-dependent wavelength shift of CD peaks. These intriguing properties of magnetoplasmonicanisotropic NWs and their self-assemblies could be consequently valuable for developing nature-inspired structural colorimprints as well as solid-state chiral sensing devices.

Automated summary

In this study, one-dimensional hybrid nanostructures with a plasmonic gold nanowire core and a shell of magnetic oxide nanoparticles were synthesized. The nanowires exhibited vivid structural colors and chiral sensing capability. These magnetoplasmonic nanostructures and their self-assemblies have promising applications.