Polymer/Ag Nanoparticles Composite for Chloroform Detection

Abstract

In this paper we report on changes in the extinction spectra of a nanocomposite consisting of Ag nanoparticles arranged in 2D array and embedded into poly(glycidyl methacrylate) host matrix. Two collective surface plasmon modes denoted as P and T were identified in the spectrum. They associated with electric dipoles perpendicular and parallel to the plane of the array respectively. It was found experimentally that intensity and bandwidth of corresponding bands decrease when the nanocomposite is exposed to chloroform vapor. At the same time, both plasmon bands shift toward shorter wavelength. Those dependences can be explained by weakening of the electrodynamic coupling between LSPR in neighboring nanoparticles due to the increase of the distance between particles caused by swelling of the polymer matrix. The spectral changes are fully reversible. It was found that sensitivity of the nanocomposite sensor to chloroform vapor is 0.02 nm/ppm with the response time $t-25\ \text{s}$.