Using a portable device based on a screen-printed sensor modified with a molecularly imprinted polymer for the determination of the insecticide fenitrothion in forest samples

摘要

A molecularly imprinted polymer is presented as a screen printed electrode (SPE) coating for determining the presence of fenitrothion in environmental samples for selective and in situ analysis. The polymeric film was obtained by electropolymerization of Ni(n)-phtalocyanine in presence of the template molecule, through the use of cyclic voltammetry. The electropolymerization process as well as the measurement of the fenitrothion by square wave voltammetry (SWV) were studied and optimized. The response of the modified SPE was linearly proportional to concentration of fenitrothion over the range of 3 × 10~(-6) to 10~(-4) mol L~(-1), with a LOD of 8 × 10~7 M and good stability and reproducibility (RSD < 14%). The selectivity of the sensor was tested by measuring fenitrothion in the presence of some possible interferent compounds such as metamitron, fenitrothion-oxon and methyl-parathion obtaining satisfactory results. The device used favours the portability of the equipment which can be used to carry out "in situ" analysis of fenitrothion in forest matrices.