Determination of parathion in vegetables by electrochemical sensor based on molecularly imprinted polyethyleneimine/silica gel films.

A novel sensor for the determination of parathion based on coupled grafting of the functional macromolecule polyethyleneimine on surfaces of silica gel particles via a surface imprinting method using molecular imprinting technology was fabricated. The electrochemical behavior of parathion at the imprinted sensor was characterized by cyclic voltammetry and linear sweeping voltammetry. The imprinted films showed high selectivity toward parathion in comparison to similar organophosphates. A linear response over parathion concentration in the range of 0.015-15 mg kg(-1) was exhibited with a detection limit of 0.003 mg kg(-1) (S/N = 3). The imprinted film sensor has been applied to the determination of parathion in spiked vegetable samples and shows promise for fast and selective determination of trace levels of parathion in real samples.