Enhanced Localized Surface Plasmon Resonance of Gold Nanoparticles Synthesized on Cellulose Nanocrystals

Plasmonic gold nanoparticles (AuNPs) exhibit a phenomenon called localized surface plasmon resonance (LSPR), making them suitable for several applications in nanotheranostics, bio-imaging and optoelectronic sensing. However, this property needs further tuning and enhancement to improve their sensitivity. Here, we developed hybrid nanocomposites by synthesizing AuNPs on the surface of cellulose nanocrystals (CNCs), with the hypothesis that confinement of collective oscillations of electrons at the interface of CNCs and AuNPs would lead to LSPR enhancement. This study uses a seed-mediated approach for growth of AuNPs on CNC surface and the ratio of gold salt to reducing agent was optimized to tune the growth. Ultraviolet/visible/near-infrared Spectroscopy, Dynamic Light Scattering, Atomic Force Microscopy and X-Ray Diffraction were used to validate hybrid formation and associated enhancement in LSPR.