Fe3O4@Au sphere molecular imprinting with self-assembled monolayer for the recognition of parathion-methyl

A novel surface molecular imprinting technique is reported based on spherical molecular imprinted monolayer (SMIM) prepared from 3-mercaptopropionic acid self-assembled on core-shell Fe3O4@Au nanoparticles (NPs) with preadsorbed templates of parathion-methyl, which is widely used in agricultural production. The proposed imprinted sensor was characterized by transmission electron microscopy (TEM), FT-IR and UV-visible absorbance spectrum analysis. The result obtained from a series of electrochemical experiments proved that the prepared sorbent had a good adsorption capacity and a fast mass transfer rate for parathion-methyl. The response of the SMIM was linearly proportional to the concentration of parathion-methyl over the range of 2.0 × 10−7 to 1.0 × 10−4 M with a lower detection limit of 1.0 × 10−7 M. The selectivity of the sensor was tested by measuring parathion-methyl in the presence of some possible interferent compounds such as imidacloprid, diuron, propanil, parathion and paraoxon and obtained satisfactory results. This imprinted electrochemical sensor was successfully employed to detect parathion-methyl with a simple surface molecular imprinting and self-assembled process which could easily and rapidly remove the template of parathion-methyl by cyclic voltammetry.