Development and validation of a cellular biosensor detecting pesticide residues in tomatoes.
Talanta
; 80(5): 1799-804, 2010 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-20152413
ABSTRACT
Two of the most important categories of pesticides used in agricultural practice are organophosphates and dithiocarbamates. Their extensive and inappropriate use has rendered their reliable monitoring at trace levels more and more necessary. This study presents the construction of a rapid and sensitive cellular biosensor test based on the measurement of changes of the cell membrane potential of immobilized cells, according to the working principle of the Bioelectric Recognition Assay (BERA). The cells were immobilized by entrapment in a sodium alginate bead and directly applied in different pesticide dilutions and agricultural samples. The pesticides used were the organophosphate insecticide diazinon and the dithiocarbamate fungicide propineb. Two different cell types, N2a (neuroblastoma) and Vero (fibroblast) were used as the biosensory elements in order to investigate their differential response against the pesticides. In this way, we hoped to increase the selectivity of the assay. Based on the observed patterns of response, we demonstrate that the sensor can be used for the qualitative and, in some concentrations, quantitative detection of the pesticides with a high degree of reproducibility. The lowest detected concentration was 3nM. Finally, for the investigation of the effects of different pesticides on the accumulation of cytosolic Ca(2+), we conducted a fluorescent assay on N2a cells treated with tomato sample extracts, which were replicates of the E.U. proficiency test sample. The tomato samples were either organically grown or contained 14 different pesticides. The experimental results showed a higher increase of the intracellular Ca(2+) concentration in cells treated with non-organic samples compared to the cells treated with organic samples.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Praguicidas
/
Zineb
/
Técnicas Biossensoriais
/
Solanum lycopersicum
/
Diazinon
Tipo de estudo:
Qualitative_research
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article