Interaction of soil humic acids with herbicide paraquat analyzed by surface-enhanced Raman scattering and fluorescence spectroscopy on silver plasmonic nanoparticles

Soil Chemical Insights Provided through Vibrational Spectroscopy

“…d Yang and Chase (1998). e Yang and Wang (1997 Humic binding mechanisms have also generated several SERS studies (Corrado et al, 2008;Leyton et al, 2008;Liang et al, 1999;Roldán et al, 2011;Sánchez-Cortés et al, 1998;Sanchez-Cortes et al, 2006;Vogel et al, 1999;Yang and Chase, 1998). In a recent study, Roldán et al (2011) utilized SERS and surface-enhanced fluorescence to investigate the interaction of humic acids extracted from a soil amended for over 30 years with cattle manure, cow slurries, crop residues, and a control sample with the herbicide paraquat (1,1′-dimethyl-4,4′-bipyridinium).…”

Fatty Acid Methyl Ester (FAME) Succession in Different Substrates as Affected by the Co-Application of Three Pesticides

“…Indeed, persistence decreased with the reduction in compost age, as resulted from comparing 12M with 3M, in accordance with our previous work [ 10 ]. However, if less mature compost is better able than mature compost to degrade pesticides, probably due to the greater carbon sources for microorganisms [ 29 ], the abundance of functional groups in a mature compost might increase the number of interactions with a pesticide and thus its persistence, as shown between a humic acid and a herbicide [ 30 ]. From these considerations, it is likely that 12M+S substrate showed an intermediate t 1/2 value between 12M and S. Note that the half-life varied to a greater extent when the interaction between pesticide and substrate was considered.…”

Silver Nanoparticles Capped with <i>p</i>-Hydroxybenzoic Acid as a Colorimetric Sensor for the Determination of Paraquat

“…It is predicted that paraquat interacts with silver nanoparticles capped with p-hydroxybenzoic acid through the mechanism of ionic interaction between the positive charge of paraquat with the anionic group phydroxybenzoic acid covering silver nanoparticles and the formation of charge transfer complexes by π-π stacking of aromatic rings. In the formation of charge transfer complexes, paraquat with high electronegativity acts as an electron acceptor, and the aromatic ring of phydroxybenzoic acid which caps silver nanoparticles acts as electron donors [27][28]. The interaction between paraquat and p-hydroxybenzoic acid covering silver nanoparticles places paraquat as a bridge between nanoparticles and results in a closer distance between the nanoparticles.…”

“…It is predicted that the interaction of paraquat with humic acid was stronger than that of silver nanoparticles so that the aggregation of silver nanoparticles capped with p-hydroxybenzoic acid facilitated by paraquat became blocked. Paraquat can interact with humic acid through ionic interactions as well as the formation of charge transfer complex [28]. The result of the determination of paraquat using silver nanoparticles capped with p-hydroxybenzoic acid was compared to another spectrophotometric method [31].…”