Competitive fluorescence assay for specific recognition of atrazine by magnetic molecularly imprinted polymer based on Fe3O4-chitosan

A novel fluorescence sensing strategy for determination of atrazine in tap water involving direct competition between atrazine and 5-(4,6-dichlorotriazinyl) aminofluorescein (5-DTAF), and which exploits magnetic molecularly imprinted polymer (MMIP), has been developed. The MMIP, based on Fe 3 O 4 -chitosan nanoparticles, was synthesized to recognize specific binding sites of atrazine. The recognition capability and selectivity of the MMIP for atrazine and other triazine herbicides was investigated. Under optimal conditions, the competitive reaction between 5-DTAF and atrazine was performed to permit quantitation. Fluorescence intensity changes at 515   nm was linearly related to the logarithm of the atrazine concentration for the range 2.32–185.4   μM. The detection limit for atrazine was 0.86   μM (S/N   =   3) and recoveries were 77.6–115% in spiked tap water samples.