resumo
The controlled release of pesticides using hydrogel vehicles is an important procedure to limit the amount of these compounds in the environment, providing an effective way for crop protection. A key-step in the formulation of new materials for these purposes encompasses the monitoring of available pesticides in the gel matrix under variable working conditions. In this work, we report a series of bionanocomposites made of Ag nanoparticles (NPs) and gelatine A for the surface enhanced Raman scattering (SERS) detection of sodium diethyldithiocarbamate (EtDTC) as a pesticide model. These studies demonstrate the effectiveness of these substrates for the detection of EtDTC in aqueous solutions in a concentration as low as 10(-5) M. We have monitored the Raman signal enhancement of this analyte in bionanocomposites having an increasing amount of gelatine due to their relevance in formulating hydrogels of variable gel strengths. Under these conditions, the bionanocomposites have shown an effective SERS activity using EtDTC, demonstrating their effectiveness in the qualitative detection of this analyte. Finally, experiments involving the release of EtDTC from Ag/gelatine samples have been monitored by SERS, which attest the potential of this spectroscopic method in the laboratorial monitoring of hydrogels for pesticide release.
palavras-chave
SURFACE-ENHANCED RAMAN; CONTROLLED-RELEASE; DITHIOCARBAMATE PESTICIDES; BIOMEDICAL APPLICATIONS; GOLD NANOPARTICLES; KAPPA-CARRAGEENAN; SODIUM ALGINATE; SCATTERING; CHITOSAN; NANOCOMPOSITES
categoria
Chemistry
autores
Fateixa, S; Soares, SF; Daniel-Da-Silva, AL; Nogueira, HIS; Trindade, T
nossos autores
Ana Luísa Daniel da Silva
Investigador Principal
Helena Isabel Seguro Nogueira
Professor Auxiliar com Agregação
Sara Fateixa
Bolseiro de pós-Doutoramento
Sofia Soares
Investigador Júnior
Tito Trindade
Professor CatedráticoProjectos
agradecimentos
S. Fateixa thanks Fundacao para a Ciencia e Tecnologia (FCT) for the Grant SFRH/BPD/93547/2013. This publication was financially supported by FEDER through Programa Operacional Factores de Competitividade - COMPETE and national funds through FCT within CICECO project - FCOMP-01-0124-FERDER-037271 (FCT Ref. Pest-C/CTM/LA0011/2013) and project PTDC/CTM-NAN/120668/2010.