Molecularly imprinted magnetic nanoparticles for determination of the herbicide chlorotoluron by gate-controlled electro-catalytic oxidation of hydrazine

摘要

We have synthesized magnetic nickel hexacyanoferrate (NiHCF) nanoparticles and coated them with a polymer that was molecularly imprinted for the herbicide chlorotoluron. The NiHCF nanoparticles coated with the molecular imprint (MIP) were then applied to prepare a sensitive, selective, and easily renewable modified electrode. Chlorotoluron can be determined indirectly based on the change in the current resulting from the oxidation of hydrazine hydrate on the modified electrode because the cavities in the MIP are increasingly blocked after binding chlorotoluron. There is a linear relationship between the response currents and chlorotoluron in the 5 x 10(-9) to 1 x 10(-7) mol center dot L-1 concentration range, and the detection limit is 9.27 x 10(-10) mol center dot L-1. This method represents an attractive platform for trace analysis of this pollutant because of (a) the advantage of "gate-controlled electro-catalytic amplification" effect, and (b) the enrichment of analyte on the magnetic particles. The renewal of the sensor was carried out by removing the disposal magnetic particles. Water samples were spiked with chlorotoluron and then assayed to give recoveries ranging from 97 % to 105 %.