A novel molecularly imprinted polymer composite based on polyaniline nanoparticles as sensitive sensors for parathion detection in the field

This paper presents a novel strategy for the real-time detection of organophosphate pesticides by imprinting parathion molecules at the surface of conductive functional polyaniline nanoparticles (PANIs). It has been demonstrated that the introduction of vinyl group on the surface of PANIs is not only beneficial to the selectivity of imprinting polymerization, but also to the preconcentration of parathion template into the polymer by charge attraction between the template and the functionalized PANIs. Through the above two effects, parathion imprinted polymer was successfully prepared on the surface of PANIs. When the novel material was used to detect parathion in vegetable samples, its selectivity coefficient was observed to be nearly ten times than that of its non-imprinted counterpart. It also possessed high selectivity toward parathion in comparison to structurally similar pesticide compounds. There was a linear relationship between the reductive peak current and parathion concentrations from testing concentrations ranging from between 3.40 × 10⁻⁸ M to 1.87 × 10⁻⁵ M with a detection limit of 1.13 × 10⁻⁸ M (S/N = 3). These results indicate that the newly developed sensor is highly effective for the detection of parathion, and establish the potential of the molecular imprinting approach for future analysis of other organophosphate pesticides.