Blueshift and Narrowing of Localized Surface Plasmon Resonance of Silver Nanoparticles Exposed to Plasma

Abstract

We have demonstrated that plasma treatments of silver nanoparticles bring about blueshift and narrowing in their localized surface plasmon resonance. Surface-enhanced Raman scattering analysis revealed that hydrocarbons adsorbed on silver surfaces were removed effectively by plasma exposure. It was found that the decrease in Raman line intensity for hydrocarbons was correlated well with the blueshift. Our findings indicate that one of the most important factors for remarkable differences in plasmon resonance wavelengths and line widths reported for the silver nanoparticles supported on substrates between most of the experimental data and calculations by Mie's theory is due to the impurity adsorption on silver surfaces.

Plasma induced enhancements in plasmonic sensitivity of sputter-deposited silver nanoparticles to ethanol vapor

“…The origin of these LSPR changes has been discussed in our previous study. 27) Furthermore, the validity of our discussion can be clarified by the simulation for extinction cross-sections of Ag NPs covered with and without carbon, as shown in Fig. 6.…”

“…Using Ar plasma alleviated the ripening rate compared to oxygen plasma. 26) In fact, Kawaguchi et al 27) reported that Ag NPs exposed to Ar plasma exhibited a sharp and blueshifted LSPR spectra as a result of the elimination of hydrocarbon initially adsorbed on the Ag NP surfaces without significant morphological changes. In this work, we thus decided to apply Ar plasma to enhance the performance of Ag NPs for volatile organic compound (VOC) vapor detection based on the LSPR.…”