以石墨烯基复合纳米材料和化学修饰酶构建有机相酶生物传感器的研究

At present defects common to organic enzyme electrodes are the low sensitivity and poor stability. It is very important to improve the sensitivity and stability of enzyme electrodes in organic solvents for the implementing the application of organic phase enzyme electrodes. In the program we first use small moleculars to chemically modify horseradish peroxidase(HRP) for the improvement the catalytic activity and stability of enzyme in organic solvents. Then,nanocomposites based on graphene and nanoporous gold, HRP chemically modified by small moleculars are organically combined to fabricate organic phase enzyme electrode. The HRP enzyme electrode is developed with high sensitivity and stability due to the synergistic effect of strong adsorption of substrate on the nanocomposites based on graphene and nanoporous gold, the capability of highly loadding enzyme,and the improvement of catalytic activity and stability of enzyme in the organic phase owing to chemical modifiers of small moleculars. The effects of small molecular chemical modifiers on the catalytic activity and stability are investigated. Using organic peroxide as model,the effects of nanocomposites, small molecular chemica modifiers and the properties of organic solvents on the electrochemistry/electro-catalysis of HRP electrode are investigated. The program offers an effective method for the solving the problem of low sensitivity of the detection of organic peroxide in non aqueous medium with HRP electrode,and has guiding significance for the development and application of organic phase enzyme electrode in non aqueous medium.

有机相酶电极的灵敏度低和稳定性较差是目前有机相酶电极的共同缺点。提高有机溶剂中酶电极的灵敏度和稳定性对实现有机相酶电极的应用具有重要意义。本项目拟先以小分子化合物修饰辣根过氧化物酶（HRP）,提高酶在有机相中的稳定性和催化活性，然后将石墨烯与纳米多孔金形成的复合纳米材料和小分子化合物修饰的HRP有机的结合起来构建有机相酶电极，通过石墨烯与纳米多孔金对底物的强吸附富集作用、对酶的高负载能力和小分子化合物修饰剂提高酶在有机相中的催化活性和稳定性的协同作用，制备高灵敏和稳定性的HRP 酶电极。研究小分子化合物修饰剂对HRP 催化活性和稳定性的影响。以有机过氧化物为模型,研究复合纳米材料、小分子修饰剂和溶剂对HRP酶电极的电化学/电催化的影响。本课题的研究不仅为非水介质中测定有机过氧化物的HRP 酶电极灵敏度低的问题提供了一种有效的方法，而且对解决酶电极在非水介质中的发展和应用具有指导意义。

过氧化物尤其是有机过氧化物在诸多领域如食品、环境控制、制药和化工等得到广泛的应用，对过氧化物的检测具有重要的意义。基于辣根过氧化物酶的电化学传感器，因其具有灵敏度高、选择性高和仪器设备简单等优点，能很好地实现对过氧化物的检测。本项目以石墨烯、碳纳米管为构建复合纳米材料的基础，以聚硫堇、聚甲苯胺蓝、聚吡咯、聚邻苯二胺、聚天青І、聚中性红等为电化学探针构建了辣根过氧化物酶传感器，及无需电化学探针构建了辣根过氧化物酶直接电化学传感器。通过复合纳米材料对底物的强吸附富集作用、对酶的高负载能力及酶的催化活性的协同作用，制备高灵敏和稳定性的辣根过氧化物酶传感器。.本项目采用扫描电镜、能谱对复合纳米材料进行了表征，采用电化学阻抗谱和循环伏安法对传感器的构建过程进行了监测。本项目制备的传感器对有机过氧化物的检测具有良好的线性范围、高的灵敏度和低的检测限。如传感器对过氧化氢异丙苯的线性检测范围为2.5×10-6 ~2.3×10-3 mol/L，检测限为1.3×10-6 mol/L。本项目的研究成果有利于开发高灵敏检测过氧化物尤其是有机过氧化物的酶传感器方法。