基于功能化石墨烯-聚乙烯醇复合膜固定乙酰胆碱酯酶的甲拌磷传感器

将功能化离子液体修饰石墨烯(IL-GR)分散在聚乙烯醇(PVA)中,制得IL-GR-PVA分散液,与乙酰胆碱酯酶(ACh E)溶液混匀后滴涂在电极表面,利用PVA良好的成膜特性,制得新型有机磷检测酶电极ACh E/IL-GR-PVA/GCE,并用于有机磷农药的检测。采用透射电镜(TEM)表征了IL-GR的形貌,采用循环伏安法(CV)和差示脉冲伏安法(DPV)研究了酶电极的电化学性质。结果表明,IL-GR-PVA复合膜具有良好的导电性和生物相容性,能很好地保持ACh E的生物活性,并显著促进了其电化学过程。在优化实验条件下,抑制率(I%)与甲拌磷浓度的负对数在1.0×10-14~1.0×10-9mol/L和1.0×10-9~1.0×10-6mol/L范围内呈良好的线性关系,检出限(S/N=3)为8.0×10-15mol/L。该传感器制备简单,稳定性好,灵敏度高,为有机磷农药的测定提供了新方法。

Study on a Phorate Biosensor Design Based on Acetylcholinesterase Immobilized with Functionalized Graphene-Polyvinyl Alcohol Nanocomposite

Ionic liquid modified graphene(IL-GR) was firstly dispersed in polyvinyl alcohol(PVA) to form IL-GR-PVA dispersion,then IL-GR-PVA and acetylcholinesterase(AChE) was mixed evenly and was coated on the glass carbon electrode via PVA film-forming.A novel biosensor was developed for the detection of organophosphorus pesticide(OP).Different techniques were employed to study the construction process and the electrochemical properties of the biosensor.The IL-GR-PVA nanocomposites with excellent conductivity and biocompatibility offered an extremely hydrophilic surface for AChE adhesion.Linear relationship between the inhibition percentage(I%) and logarithm of phorate concentration was found in the ranges of 1.0×10-14-1.0×10-9 mol/L and 1.0×10-9-1.0×10-6 mol/L,with a detection limit(S/N=3) of 8.0×10-15 mol/L.The easily prepared electrochemical sensor has a favorable stability and sensitivity,thus providing a new OPs detection method