基于等离子体修饰的PVC膜脲酶传感器

报道了一种基于等离子体修饰的PVC膜脲酶生物传感器。应用微波等离子体化学气相沉积技术,在pH敏感PVC膜上修饰一层带有氨基的乙二胺等离子体聚合物薄层,通过戊二醛共价交联固定脲酶分子,制成脲酶传感器。这种乙二胺等离子体聚合物薄层对pH敏感膜的响应特性影响小,且其表面氨基使得pH敏感膜更加易于与H+结合,检测范围向高pH方向偏移,响应斜率为45.73mV/pH,比未修饰的pH敏感膜电极的响应斜率42.81mV/pH有所提高。该脲酶传感器对尿素显示了良好的传感性能,其响应时间约为200s;在6.0×10-4~8.4×10-3mol/L范围,脲酶传感器的电位响应值与尿素浓度的对数存在良好的线性关系,相关系数为0.9978,检测下限为5.0×10-5mol/L。

A new urease biosensor based on the plasma-modified pH-sensitive PVC membrane

A new urease biosensor based on the plasma-modified PVC membrane has been developed. Using microwave plasma technique, an ethylene diamine plasma-polymerized layer with amine groups was first deposited on the pH-sensitive PVC membrane. The abundant amide groups make the plasma-modified pH-sensitive membrane easier to bind H+, and thus the response range of the pH sensitive membrane has some shift toward high pH value and the response slope of 45.73 mV/pH is over that of common pH sensitive membrane, 42.81 mV/pH, showing an enhancing pH response. After activated with 2.5% glutaraldehyde solution, urease molecules were covalently immobilized onto the plasma-polymerized pH-sensitive PVC membrane surface and the urease biosensor was then obtained. The urease biosensor has a response time of less than 200 s and a detection limit of 5.0 ? 10-5 mol/l, and there is a good linear relationship between the potential response and the logarithm value of the urea concentration in the range of 8.4 ? 10-3 ~ 6.0 ? 10-4 mol/l with an interrelated coefficient of 0.9978.