Electrochemical Surface-Enhanced Raman Spectroscopy (EC-SERS) and Computational Study of Atrazine: Toward Point-of-Need Detection of Prevalent Herbicides
Najwan Albarghouthi, Maddison Eisnor, Cory C. Pye, Christa L. Brosseau
Abstract
This paper presents an electrochemical SERS (EC-SERS) and computational study of the common herbicide atrazine. Herein, we highlight that the atrazine molecule shows a clear potential-dependent SERS signal that manifests as two different adsorption orientations at the nanostructured silver surface. This finding is supported by computational work and indicates that the initial adsorption orientation is perpendicular to the surface with the C–Cl moiety pointed away from the surface, and upon stepping to negative applied voltages, the atrazine molecule rotates such that the C–Cl and isopropyl moieties are orientated more planar to the surface, while the molecule remains oriented perpendicular to the surface. To the best of our knowledge, this paper represents the first EC-SERS study of atrazine and paves the way for a rapid point-of-need detection tool for atrazine monitoring in the environment wherein an enhanced signal can be detected at negative applied voltages.