Electrochemical Characterization of Mancozeb Degradation for Wastewater Treatment Using a Sensor Based on Poly (3,4-ethylenedioxythiophene) (PEDOT) Modified with Carbon Nanotubes and Gold Nanoparticles.

Mancozeb is a worldwide fungicide used on a large scale in agriculture. The active component and its main metabolite, ethylene thiourea, has been related to health issues. Robust, fast, and reliable methodologies to quantify its presence in water are of great importance for environmental and health reasons. The electrochemical evaluation of mancozeb using a low-cost electrochemical electrode modified with poly (3,4-ethylene dioxythiophene), multi-walled carbon nanotubes, and gold nanoparticles is a novel strategy to provide an in-situ response for water pollution from agriculture. Additionally, the thermal-, electrochemical-, and photo-degradation of mancozeb and the production of ethylene thiourea under controlled conditions were evaluated in this research. The mancozeb solutions were characterized by electrochemical oxidation and ultraviolet-visible spectrophotometry, and the ethylene thiourea concentration was measured using ultra-high-performance liquid chromatography high-resolution mass spectrometry. The degradation study of mancozeb may provide routes for treatment in wastewater treatment plants. Therefore, a low-cost electrochemical electrode was fabricated to detect mancozeb in water with a robust electrochemical response in the linear range as well as a quick response at a reduced volume. Hence, our novel modified electrode provides a potential technique to be used in environmental monitoring for pesticide detection.

What are the Main Sensor Methods for Quantifying Pesticides in Agricultural Activities? A Review.

In recent years, there has been an increase in pesticide use to improve crop production due to the growth of agricultural activities. Consequently, various pesticides have been present in the environment for an extended period of time. This review presents a general description of recent advances in the development of methods for the quantification of pesticides used in agricultural activities. Current advances focus on improving sensitivity and selectivity through the use of nanomaterials in both sensor assemblies and new biosensors. In this study, we summarize the electrochemical, optical, nano-colorimetric, piezoelectric, chemo-luminescent and fluorescent techniques related to the determination of agricultural pesticides. A brief description of each method and its applications, detection limit, purpose-which is to efficiently determine pesticides-cost and precision are considered. The main crops that are assessed in this study are bananas, although other fruits and vegetables contaminated with pesticides are also mentioned. While many studies have assessed biosensors for the determination of pesticides, the research in this area needs to be expanded to allow for a balance between agricultural activities and environmental protection.

Conductive nanostructured materials based on poly-(3,4-ethylenedioxythiophene) (PEDOT) and starch/κ-carrageenan for biomedical applications.

Smart electroactive biomaterials are sought to allow the direct delivery of electrical, electrochemical and electromechanical signals to biological tissues. Specifically, poly-(3,4-ethylenedioxythiophene) (PEDOT) is a polymer of special interest attending to its biocompatibility, tuneable electrical conductivity and processing versatility. In this work, nanostructured PEDOT was synthesized using starch/κ-carrageenan aerogels as templates. κ-carrageenan biopolymer acted as doping agent of the conductive polymer to enhance the biocompatibility and the electrical response. The physicochemical, morphological, mechanical and electrical properties of the nanostructured PEDOT and templates were characterized. The incorporation of κ-carrageenan to the nanostructured materials resulted in an increase in the compressive strength of ca. 40% and a decrease in the electrical impedance of one order-of-magnitude. The synergistic combination of the inherent electrical properties of the PEDOT, the advantageous features of κ-carrageenan as doping agent and the porous morphology of the aerogel template resulted in electroactive PEDOT nanostructures with relevant properties for biomedical applications.