功能化石墨烯固载单原子金属的可控合成及电化学无酶传感研究

Electrochemical non-enzymatic sensors, the forth-generation glucose sensor, have shown promising potential for application in glucose detection. The electro-catalysts is the key to develop novel electrochemical non-enzymatic sensor with high performance. Variety of nanostructured metals, metal oxides, carbon materials, etc., have been extensively studied in electrochemical non-enzymatic sensors and shown highly electrocatalytic activity towards glucose. However, Several key problems, such as low current response, narrow detection range, interference of interferent, and unclear catalytic mechanism, are still urgently needed to solve. Single atom metal catalysts have drawn increasing attention in recent years due to their high catalytic efficiency and selectivity. However, the application of single atomic catalyst in the field of electrochemical enzyme-free sensor is still rare. Therefore, we plan to fabricate highly dispersed and high-load single atom metal catalyst supported by functionalized graphene as a carrier, which is an ideal carrier with high conductivity and specific surface area. With the high catalytic activity and stability of single atomic catalysts, the electrochemical non-enzymatic sensors will be constructed by single atomic metal/functional graphene composite materials. The catalytic mechanism of glucose oxidation on the single atom catalysts will be also studied to explore the relationship between the structure of single atom catalyst and sensing performance. The performance of electrochemical non-enzymatic sensor will be greatly improved by optimizing the structure and component of single atom catalyst. This study will provide important theoretical and experimental progress to develop new generation electrochemically non-enzymatic sensors.

电化学无酶传感器，作为第四代葡萄糖传感器，在葡萄糖检测中显示出巨大潜力与应用价值。其中，催化剂是发展高性能无酶传感器的关键。具有各种纳米结构金属、金属氧化物、碳材料等对葡萄糖展示了高效的催化活性，在电化学无酶传感器中得到广泛的研究。但是，电化学无酶传感器还存在较低的电流响应、检测范围窄、易受干扰物干扰以及催化氧化机制不完全清楚等问题。近年来，单原子金属催化剂由于具有高的催化效率和选择性，逐渐受到人们的广泛关注。然而，将单原子催化剂应用在电化学无酶传感领域的研究还非常少见。所以，本项目将以功能化石墨烯为载体，制备负载高分散和高负载量的单原子金属催化剂，利用单原子催化剂高效稳定和高选择性的特点，构建单原子金属/功能化石墨烯电化学无酶传感器，深入研究对葡萄糖的催化机理以及材料结构与性能之间的关系，大大提高无酶传感器的性能，为电化学无酶传感器的发展提供重要的实验和理论基础。

发展特定的非酶催化剂对构建新型电化学非酶葡萄糖传感器是电化学传感领域的重要挑战之一。已被广泛研究的各种纳米结构材料在电化学非酶葡萄糖领域虽然展示了较好的潜力，但是其传感性能还有待提高，更重要的是其对葡萄糖的催化机理还不清楚。因此，本项目主要研究内容是采用具有100%原子利用率的单原子金属催化剂，利用其独特高效、高选择性的催化特性和明确结构的催化活性中心，构建了一系列单原子金属催化剂为基的高性能的电化学非酶葡萄糖传感器，并研究了单原子催化剂对葡萄糖的催化作用机理。主要研究结果包括：1) 首先成功制备了多种用于负载贵金属单原子的功能纳米结构材料的载体，如Ni(OH)2/氮掺杂的石墨烯(NG)、Co掺杂的层状氢氧化镍(Ni6Co1LDH)/NG、NiO/NG、Cu和Cu@CuxO纳米线/纳米管、多孔碳纤维薄膜等；2）利用浸渍法和置换法在上述载体的表面固定稳定的贵金属单原子，制备了 Pt、Ir和Ru等贵金属单原子催化剂，比如，Pt1/Ni(OH)2/NG、Pt1/Ni6Co1LDH/NG、Ir1/NiO/NG、Pt1/Cu@CuO核壳纳米线、Ru1/Cu@Cu2O空心纳米管等，通过同步辐射和球差电镜等表征证明了单原子金属催化剂的成功合成；3）通过电化学测试手段，发现所得的单原子催化剂材料表现出比纳米催化剂具有更低的起始电位和更高的响应电流，说明单原子金属的引入大大提高了材料对葡萄糖电催化性能。以单原子催化剂为基的电化学非酶传感器对葡萄糖具有高灵敏度、宽线性范围、更低的检测限、优异的选择性和良好的稳定性。结合DFT计算结果证明，单原子催化剂的高效催化和传感性能可归因于单原子金属对葡萄糖具有较强的吸附能力以及单原子金属与载体的电子相互作用。这些研究结果不仅展示了单原子金属催化剂对葡萄糖具有优异的电化学非酶传感性能，还揭示了催化过程中单原子活性中心的催化机制，表明单原子催化剂在电化学非酶葡萄糖传感领域具有潜在的应用前景，为开发新一代的电化学非酶葡萄糖传感器提供了理论和实验依据。