石墨烯增敏莱克多巴胺分子印迹电化学传感器

摘要

采用两步修饰的方式,先通过恒电位还原,将易分散于水的氧化石墨烯还原至玻碳电极表面形成均匀的还原氧化石墨烯修饰膜,再以吡咯为功能单体,采用电化学原位印迹技术制备了以莱克多巴胺(RAC)为模板分子的分子印迹聚合物膜,由此构建了用于莱克多巴胺的选择性灵敏测定的电化学印迹传感器.实验结果发现,在优化条件下,RAC的DPV响应电流在浓度为1.0×10-7～7.0×10-6 mol/L范围内呈现良好的线性关系,且传感器对RAC具有良好的重现性(RSD=1.9％,n=7).在印迹前修饰rGO,使印迹膜传感器对RAC的亲和力增强,响应速度提高,吸附量增加4.32倍,且其印迹因子IF=2.36,反映了良好的印迹效果及增敏效应.%In this paper, a molecular imprinting polymers and reduced grphene oxide (MIPs/rGO) based sensor was constructed for ractopamine by two steps operation on Glassy carbon Electrode(GCE).This MIPs was formed by using pyrrole as monomer and ractopamine as template molecular.Prior to that, reduced graphene oxide(rGO) was formed on GCE surface by electrochemical reducing the graphene oxide(GO) suspension.Based on the sensitizing effect of rGO and specific recognition of MIPs, the proposed sensor showed a satisfactory molecularly binding selectivity of RAC against its common structural analogues, and there was a linear response to RAC concentration range from 1.0×10-7 mol/L to 7.0×10-6 mol/L under the optimized conditions.Meanwhile, good stability(RSD=1.9％, n=7) was observed.Compared to NIPs/rGO based sensor, the MIPs/rGO based sensors have a stronger affinity to RAC with an imprinting factor(IF) of 2.36 and high absorption ratio of 4.32 that reflected the distinct synergistic effect of molecular imprinting and rGO.