高表面积纳米多孔金/可变价态过渡金属氧化物复合材料的制备及对葡萄糖的无酶分析

Non-enzymatic glucose electrochemical sensors have gained much attention in the field of glucose sensors, and the key factor is to develop electrode nanomaterials which can directly electro-oxidize glucose and to rationally design and build electrode structures for high performance electrooxidation of glucose. This project is planned to construct novel high-surface-area nanoporous gold/ nanostructured variable valence transition metal oxide two oxidation centers composites to improve the stability, sensitivity and other indicators of non-enzymatic glucose sensors. Different variable valence transition metal oxide nanomaterials will be loaded onto/into a nanoporous gold support that is prepared by anode potential step technology and nanoporous gold and transition metal oxide performed as two oxidation centers to electro-oxidize glucose; to investigate the effects of various types and concentrations of Cl ions-containing electrolytes, step potentials and step time, temperature and other factors on the formation and evolution of the pore sizes and structures of nanoporous gold; to demonstrate the electrocatalytic nature of nanoporous gold and how the interfacial structural characteristics between nanoprous gold and transition metal oxide with different structures and valences influence the electro-catalytic performance of glucose. From this basis, we will regulate compositions and structures of the composites to improve their catalytic activities; to reveal the synergetic/coupling effect of the two oxidation centers and the enhanced electrocatalytic oxidation mechanism of glucose combined with theoretical calculations. This project will provide the theoretical and experimental basis necessary for the development of non-enzymatic electrochemical glucose sensor.

无酶葡萄糖电化学传感器在葡萄糖传感器研究领域倍受关注，其关键是开发对葡萄糖有直接电催化活性的纳米电极材料和合理设计构筑性能优异的电极结构。本项目拟在阳极电势阶跃法制备的纳米多孔金基底上负载不同种类的可变价态过渡金属氧化物纳米材料，构筑新型高表面积纳米多孔金/可变价态过渡金属氧化物双氧化中心复合电极，以提高无酶葡萄糖传感器的稳定性、灵敏度等性能指标。主要研究含氯电解液的性质和浓度、阶跃电势和时间、温度等因素的改变对纳米多孔金的孔径、结构的形成和演化的影响规律；阐明纳米多孔金的电催化本质特征及纳米多孔金与不同结构和价态的过渡金属氧化物之间的界面结构特征和葡萄糖电催化性能的相互关系，通过调控复合材料的组成和结构提高其催化活性；结合理论计算，揭示纳米多孔金-过渡金属氧化物双氧化中心的协同/耦合作用及其电催化氧化葡萄糖的作用机制，为无酶葡萄糖传感器的研制提供理论和实验依据。

对葡萄糖的高敏快速检测是及时预防和治疗糖尿病的重要保障。目前研究和应用最多的是有酶型葡萄糖传感器，但酶分子固有的不稳定性影响了其应用的长期性和准确性。无酶葡萄糖电化学传感器利用葡萄糖在电极表面的直接电化学氧化对其进行检测，避免了酶传感器的不足。纳米多孔金（NPG）比表面积大、生物兼容性好且对葡萄糖分子有直接的高催化活性，是构建无酶葡萄糖电化学传感器的理想材料。本项目发展了在各种含氯电解液中阳极化Au电极一步高效制备纳米多孔金（NPG）的方法，该方法绿色温和，无需任何有机物参与和产生，无需高温，无需模板。深入研究了阳极阶跃电势、阳极化时间、含Cl–电解液的种类和浓度等对所制备的NPG的粒径尺寸、电化学活性面积、表面组成的影响，基本实现了NPG的可控制备；系统考察了NPG的电化学性质及其对葡萄糖的电催化性能，结果表明NPG的电化学活性面积和其对葡萄糖的检测灵敏度在一定范围内呈正相关，即具有更高表面积的NPG对葡萄糖检测的灵敏度越大；以高表面积NPG为基底，通过电化学方法分别制备了NPG/Ni(OH)2、NPG/Cu、NPG/CoOx三类复合电极，用时均不到20分钟，快速构建了高敏无酶葡萄糖电化学传感界面。这三类电极对葡萄糖具有快速响应性、良好的选择性和稳定性，均成功用于人血清样品中葡萄糖含量的检测。项目的研究成果为血糖的电化学无酶快速检测装置提供了重要的研究意义和应用价值。