Abstract: A molecularly imprinted polymer membrane electrochemical sensor for detection of herbicide bensulfuronmethyl (BSM) was constructed by electropolymerization of o-aminophenol (oAP) onto a gold electrode in the presence of herbicide BSM molecule. The imprinted electrode was prepared via cyclic voltammetric scans in the range of -0.4 ~ +0.8 V for 20 cycles in a solution consisting of 5 mL of 10 mmol/L oAP and 5 mL of 5 mmol/L BSM,which was purged with nitrogen for 5 min before being used. The template molecule was removed by immersing the resulting electrode in an acetonitrile and deionized water (1:2, V/V) solution at room temperature under continuous agitation. The modification procedure of the imprinted sensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. And the intermolecular interaction between BSM and oAP was confirmed by ultraviolet spectroscopy. The recognition performance of the imprinted sensor was investigated by measuring the differential pulse voltammetric (DPV) response of the oxidation-reduction probe, K3Fe(CN)6 on the electrode. The results showed that the best eluting effect was obtained from a solution consisting of acetonitrile and water (1/2, V/V). The peak current of K3Fe(CN)6 decreased linearly in the concentration range of BSM from 2. 5 to 180 μmol/L (R2 = 0.997) with a detection limit of 0.8 μmol/L. And the response time was closed to 5 min. In addition, the studied imprinted sensor exhibited high affinity and long-term stability. And the imprinted sensor demonstrated higher selectivity for target BSM over competitive, possessing analogous structures and common coexisting substance, herbicide pyrazosulfuron-ethyl (PES) and terbuthylazine (TB). The proposed imprinted sensor was successfully applied to the determination of BSM in environmental water samples with the recoveries from 95.1% to 100.5%.
Template and target information: bensulfuronmethyl, BSM
Author keywords: Electrochemical sensor, molecular imprinting technique, electropolymerization film, Bensulfuronmethyl