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|Título:||Biosensor based on multi-walled carbon nanotubes paste electrode modified with laccase for pirimicarb pesticide quantification|
|Autor:||Oliveira, Thiago M. B. F.|
Barroso, M. Fátima
Lima-Neto, Pedro de
Correia, Adriana N.
Oliveira, M. Beatriz P. P.
Multi-walled carbon nanotubes
|Relatório da Série N.º:||Talanta; Vol. 106|
|Resumo:||This study focused on the development of a sensitive enzymatic biosensor for the determination of pirimicarb pesticide based on the immobilization of laccase on composite carbon paste electrodes. Multi- walled carbon nanotubes(MWCNTs)paste electrode modified by dispersion of laccase(3%,w/w) within the optimum composite matrix(60:40%,w/w,MWCNTs and paraffin binder)showed the best performance, with excellent electron transfer kinetic and catalytic effects related to the redox process of the substrate4- aminophenol. No metal or anti-interference membrane was added. Based on the inhibition of laccase activity, pirimicarb can be determined in the range 9.90 ×10- 7 to 1.15 ×10- 5 molL 1 using 4- aminophenol as substrate at the optimum pH of 5.0, with acceptable repeatability and reproducibility (relative standard deviations lower than 5%).The limit of detection obtained was 1.8 × 10-7 molL 1 (0.04 mgkg 1 on a fresh weight vegetable basis).The high activity and catalytic properties of the laccase- based biosensor are retained during ca. one month. The optimized electroanalytical protocol coupled to the QuEChERS methodology were applied to tomato and lettuce samples spiked at three levels; recoveries ranging from 91.0±0.1% to 101.0 ± 0.3% were attained. No significant effects in the pirimicarb electro- analysis were observed by the presence of pro-vitamin A, vitamins B1 and C,and glucose in the vegetable extracts. The proposed biosensor- based pesticide residue methodology fulfills all requisites to be used in implementation of food safety programs.|
|Versão do Editor:||http://www.sciencedirect.com/science/article/pii/S003991401201051X|
|Aparece nas colecções:||ISEP – GRAQ – Artigos|
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|ART_ThiagoOliveira_2013_GRAQ.pdf||635,33 kB||Adobe PDF||Ver/Abrir Acesso Restrito. Solicitar cópia ao autor!|
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