Nanocristais na Detecção de Glifosato

Abstract

Glyphosate is a toxicologically harmful herbicide with potential association with human carcinogenesis and other chronic diseases, including mental and reproductive behavior. The difficulties in detecting and demonstrating their toxicity are probably due to their metal chelating properties, the interference of organic compounds in the environment and the similarity with their byproducts. As a result, high costs for detecting this pesticide result in the absence of public policies. Once the glyphosate chelating properties, we tested the detection capacity of the complex formed by this herbicide and some metal oxide nanocrystals under various pH conditions, using spectroscopic methods through an Infrared Equipment, whose results are presented after the Fourier Transform (FTIR) and a Coupled Evanescent Wave Sensor. The first chapter was published by Environmental Chemistry Letters and presents the largest literature review containing all available glyphosate detection and quantification technologies of the past 36 years, including their disadvantages and advantages. The purpose of this chapter is to create a theoretical foundation demonstrating the current status of knowledge about glyphosate detection methods that may justify the use of nanocrystals in its detection.

The second chapter was submitted to The Journal of Physical Chemistry Letters. The ZnO glyphosate-nanocrystalline interaction was investigated by FTIR, scanning electron microscopy (SEM) and atomic force microscopy (AFM) to theorize its chemical and physical properties. This study underpins the experimental essays of the next chapters. The third chapter was submitted to Analytical Chimica Acta in August 2019. This chapter demonstrates that zinc oxide nanocrystals are potent FTIR spectral promoters for glyphosate samples while silver oxide nanocrystals have superior chelating properties at neutral pH. The fourth chapter was submitted to Sensors and Actuators Reports in September 2019. The aim of this study was to demonstrate the possibility that Glyphosate could be detected by a portable cell-surface resonance plasmonic equipment by complexing the herbicide with nanocrystals. copper oxide, and under a specific protonation condition.