Characterization of valeric acid using substrate of silver nanoparticles with SERS

The motive of this work is to study the molecular interaction between valeric acid (VA) molecules as analyte and silver nanoparticles as substrates. Therefore, a new approach was established for an efficient detection of VA using the surface enhanced Raman scattering (SERS) technique. Silver nanoparticles (Ag-NPs) were synthesized by the reduction procedure and used as a SERS substrate for the detection of VA. The structure and morphology of the silver nanoparticles were characterized by Raman spectroscopy, UV spectroscopy, and transmission electron microscopy. The UV-visible spectra showed a maximum absorption of around 420 nm for the synthesized Ag-NPs. TEM image showed the spherical structure of the Ag-NPs. Possible modes of VA-Ag-NP interactions resulting in SERS enhancement were investigated via density functional theory (DFT) calculations. The most enhanced SERS band was utilized for a trace identification of VA in aqueous media. A calibration curve was established with a wide dynamic range, and a detection limit of 10 x 10(-)(10) M of VA was successfully achieved. The results support further enhancement in the applications of SERS in trace level detection of different targets. (C) 2018 Elsevier B.V. All rights reserved.