Morphology-dependent MnO2/nitrogen-doped graphene nanocomposites for simultaneous detection of trace dopamine and uric acid
Morphology-dependent MnO2/nitrogen-doped graphene nanocomposites for simultaneous detection of trace dopamine and uric acid
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形态依赖的MnO2/氮掺杂石墨烯纳米复合材料用于同时检测痕量多巴胺和尿酸
DOI：
10.1016/j.msec.2019.110615
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发表时间：
2020-04-01
影响因子：
7.9
通讯作者：
Li, Guangli
中科院分区：
文献类型：
--
作者：
Li, Qing;Xia, Yonghui;Li, Guangli
合成了四种形貌可控的纳米MnO2，包括纳米线、纳米棒、纳米管和纳米花，并在超声作用下与氮掺杂石墨烯（NG）复合。采用多种技术研究了MnO2/NG纳米杂化材料的表面形貌、相结构和电化学性能，并比较了它们对多巴胺（DA）和尿酸（UA）电氧化的催化活性。传感性能被发现是高度相关的，其形态。在这些形貌中，与NG复合的纳米花状MnO 2显示出对DA和UA最敏感的响应信号。其电催化活性的提高主要归因于其独特的多孔结构、较大的电活性面积和较低的电荷转移电阻（R-ct），有利于电极与分析物之间的电子转移。两个线性响应范围（0.1 μ M-10 μ M和10 μ M-100 μ M）的DA和UA，分别伴随着非常低的检测限为34 nM和39 nM。此外，MnO2 NFs/NG复合材料的成功应用于同时检测人血清中的DA和UA使用二阶导数线性扫描伏安法（SDLSV）实现。这些发现为理解MnO2基纳米材料的形貌依赖的传感特性提供了有价值的见解，这有利于普遍存在的MnO2基电化学传感器的快速发展。
Four nanostructured MnO2 with various controllable morphologies, including nanowires, nanorods, nanotubes and nanoflowers were synthesized, and then further composited with nitrogen-doped graphene (NG) with the assistance of ultrasonication. The surface morphologies, phase structures, and electrochemical performances of the proposed MnO2/NG nanohybrids were investigated by various techniques, and their catalytic activities on the electrooxidation of dopamine (DA) and uric acid (UA) were compared systematically. The sensing performances were found to be highly correlated with their morphologies. Among these morphologies, the nanoflowerlike MnO2, composited with NG, displayed the most sensitive response signals for DA and UA. The boosted electrocatalytic activity was ascribed to the unique porous structure, large electroactive area, and low charge transfer resistance (R-ct), which facilitated the electron transfer between electrode and analyzes. Two linear response ranges (0.1 mu M-10 mu M and 10 mu M-100 mu M) were accompanied with very low detection limits of 34 nM and 39 nM for DA and UA, respectively. Moreover, the successful application of the MnO2 NFs/NG composites for the simultaneous detection of DA and UA in human serum was realized using second-derivative linear sweep voltammetry (SDLSV). These findings give valuable insights for understanding the morphology-dependent sensing properties of MnO2 based nanomaterials, which is conducive to the rapid development of ubiquitous MnO2-based electrochemical sensors.