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

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

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。

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（ ACh E） 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 ACh E 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- 9mol / L and 1. 0 × 10- 9-1. 0 × 10- 6mol / 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.