Detection of herbicides atrazine and prometryn via Raman amplified surface (SERS)

Author(s)

Rafael Jesus Gonçalves Rubira

• Document type: Master's Dissertation
• Press: Bauru. 2016-08-17.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru
• Defense date: 2016-07-22
• Advisor: Carlos José Leopoldo Constantino

Abstract

The atrazine and prometryne herbicides belong to the class of s-triazines, having properties that cause harm in humans and are classified as toxic agents. This thesis for the Master Qualification Examination General is part of the master project whose main objective is to investigate the detection of atrazine and Prometryn herbicides using surfaceenhanced Raman scattering (SERS) that has high sensitivity and selectivity in analyte detection, being sensory application the broader objective of this project. The herbicides are dissolved in various concentrations of silver colloids (AgNPs: silver nanoparticles). The atrazina was detected in concentration of order 10-12 mol/L in ultrapure water with good resolution signal noise and 10-11 mol/L in deionized water. The prometryn also presented detection in ultrapure water with concentrations of order 10-12 mol/L and for systems with deionized water and tap on the order of 10-9 mol/L. These values are below the limits of potable water allowed by regulatory agencies (1.39 x 10-8 mol/L atrazine and 9.62 x 10-8 mol/L for prometryn), these limits that represent an analytical challenge by itself. In addition, the SERS spectra were classified by computer techniques of information visualization, enabling better data analysis. In terms of adsorption mechanisms for solutions ultrapure water, atrazine adsorbs on AgNPs via C atom of the radical ethyl and Cl and prometryn have their triazínico ring positioned parallel to the surface of AgNPs adsorbing via C-S atoms. Such mechanisms could not be determined for deionized and tap water. In addition were carried impedance spectroscopy measurements at the detection of both herbicides in LbL PAH/AgNPs films. (AU)

• FAPESP's process: 14/00244-0 - Detection of herbicides atrazine and prometryn via Raman amplified surface (SERS)
• Grantee: Rafael Jesus Gonçalves Rubira
• Support Opportunities: Scholarships in Brazil - Master