Investigation on electrochemical preparation of methyl parathion imprinted film modified electrode and its application.

Molecularly imprinted porous silicate film modified glassy carbon electrode was prepared by electrochemical modulation of pH at the electrode/solution interface to promote controlled gelification of teraethylorthosilicate(TEOS)sol with constant potential using methyl parathion(MP)as template and phenyltriethoxysilane(PTEOS)as functional monomer.The molecularly imprinted film was characterized with scanning electron microscopy,X-ray diffraction and electrochemical techniques.Electrochemcial behaviors of methyl parathion on the imprinted and nonimprinted film electrode were investigated with voltammetry.It was found that the response and selectivity of methyl parathion on the imprinted film electrode were significantly improved.Under the optimal conditions,the oxidation peak current was proportional to methyl parathion concentration in the range of 1.0 × 10-8 mol·L-1 to 1.0 × 10-5 mol·L-1 by following equation:Ip(μA)= 1.283 9 c(μmol·L-1)+ 0.438 6(R=0.999 8)with a detection limit of 9.2 × 10-9 mol·L-1.This imprinted film electrode was successfully used in the selective detection of methyl parathion in apple samples.