Surface-Enhanced Raman Analysis of p-Nitroaniline on Vacuum Evaporation and Chemically Deposited Silver-Coated Alumina Substrates

Abstract

In this study we investigated the surface-enhanced Raman scattering (SERS) properties of p-nitroaniline, which is a potential chemical for use in optical disk coating(s) and also an important compound used as an intermediate or precursor in the manufacture of chemical agents, pesticides, pharmaceuticals, dyes, and antioxidants. The SERS spectra of p-nitroanaline ( p-NA), adsorbed on or near the surface of either vacuum thermally evaporated or chemically prepared silver-coated alumina substrates, have been recorded in the frequency region from 200 to 1800 cm−1. The performances of these substrates to enhance the Raman scattering signals were not possible to compare with each other because of different experimental conditions. The infrared (IR) (500–1800 cm−1) and Raman (200–1800 cm−1) spectra have been recorded for the solution of p-NA. Vibrational assignments were made for the molecule in the frequency region. The Raman enhancement factor was estimated to be on the order of 106, and the absolute limit of optical detection was determined to be 30 femtograms.