以玻碳电极为基底,电聚合邻氨基苯甲酸(ABA),使其形成带负电的界面,通过分子间静电作用力,自组装一层带正电荷的电子媒介体甲苯胺蓝(TB),再通过媒介体的氨基吸附纳米金,最后静电吸附固定辣根过氧化物酶制备出H2O2传感器.探讨了膜聚合时间、媒介体组装时间、pH、温度、工作电位对电极响应的影响.在优化的实验条件下,该传感器对H2O2电流响应与其浓度为1.5×10^-5~1.3×10^-3 mol/L范围内呈线性关系;检出限为5.6×10^-6mol/L.此外,该传感器具有较低的工作电位,能有效地消除抗坏血酸等的干扰.
A novel approach by means of self-assembled technique and opposite-charged adsorption to immobilize horseradish peroxidase (HRP) to fabricate amperometric biosensor. The electrode architecture was fabricated by positively charged toluidine blue coated on negatively charged poly-2-aminobenzoic acid (PABA) modified glassy carbon electrode surface through electrostatic interactions to form a composite TB/PABA membrane, which yielded an interface containing amine groups to assemble gold nanoparticles for immobilization of HRP. The effects of experimental conditions such as the polymerization time of PABA, assembling-time for mediator, pH, temperature and applied potential on the electrode performance have been investigated. The linear response of the sensor to H2O2 iS in the range of 1.5×10^-5~1.3×10^-3 mol/L with a detection limit of 5.6×10^-6mol/L in0.1 mol/L PBS (pH 6.5) at -0.25 V. The current response time is 10 s. The biosensor retained 83.6% of its original activity after three weeks of use. Moreover, the studied biosensor exhibited good reproducibility, selectivity and high sensitivity.