College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
Nanoscale. 2015 Jan 28;7(4):1290-5. doi: 10.1039/c4nr05325g.
In recent years, graphene-based enzyme biosensors have received considerable attention due to their excellent performance. Enormous efforts have been made to utilize graphene oxide and its derivatives as carriers of enzymes for biosensing. However, the performance of these sensors is limited by the drawbacks of graphene oxide such as slow electron transfer rate, low catalytic area and poor conductivity. Here, we report a new graphene-based enzyme carrier, i.e. a highly conductive 3D nitrogen-doped graphene structure (3D-NG) grown by chemical vapour deposition, for highly effective enzyme-based biosensors. Owing to the high conductivity, large porosity and tunable nitrogen-doping ratio, this kind of graphene framework shows outstanding electrical properties and a large surface area for enzyme loading and biocatalytic reactions. Using glucose oxidase (GOx) as a model enzyme and chitosan (CS) as an efficient molecular binder of the enzyme, our 3D-NG based biosensors show extremely high sensitivity for the sensing of glucose (226.24 μA mM(-1) m(-2)), which is almost an order of magnitude higher than those reported in most of the previous studies. The stable adsorption and outstanding direct electrochemical behaviour of the enzyme on the nanocomposite indicate the promising application of this 3D enzyme carrier in high-performance electrochemical biosensors or biofuel cells.
近年来，基于石墨烯的酶生物传感器因其优异的性能而受到广泛关注。人们付出了巨大的努力，利用氧化石墨烯及其衍生物作为酶的载体来进行生物传感。然而，这些传感器的性能受到氧化石墨烯的一些缺点的限制，如电子转移速率慢、催化面积小和导电性差。在这里，我们报告了一种新的基于石墨烯的酶载体，即通过化学气相沉积生长的高导电性 3D 氮掺杂石墨烯结构（3D-NG），用于高效的基于酶的生物传感器。由于高导电性、大孔率和可调的氮掺杂比，这种石墨烯框架表现出优异的电学性能和大的表面积，用于酶的负载和生物催化反应。使用葡萄糖氧化酶（GOx）作为模型酶和壳聚糖（CS）作为酶的高效分子结合物，我们的基于 3D-NG 的生物传感器对葡萄糖的传感表现出极高的灵敏度（226.24 μA mM(-1) m(-2)），几乎比之前大多数研究报告的灵敏度高一个数量级。酶在纳米复合材料上的稳定吸附和出色的直接电化学行为表明，这种 3D 酶载体在高性能电化学生物传感器或生物燃料电池中有很好的应用前景。
