Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, Hubei, P. R. China.
Nanoscale. 2020 Apr 28;12(16):9014-9023. doi: 10.1039/c9nr10944g. Epub 2020 Apr 9.
The development of crystal-facet metal oxide heterostructures has been of great interest owing to their rational design and multifunctional properties at the nanoscale level. Herein, we report a facile solution-based method for the synthesis of single-crystal CuO nanostructures (i.e. CuO-CuO) as a core. Graphene quantum dots (GQDs) with varying concentrations are fabricated on the surface of CuO extended hexapods (EHPs) in ethanol solution at room temperature via self-assembly, where copper acts as a sacrificial model and a stabilizer as well. The CuO crystals displayed a good sensing activity toward BPA oxidation owing to their high energy facets, dangling bonds and great proportion of surface copper atoms. Structural, morphological, chemical and vibrational investigations were performed in detail, presenting high crystallinity of hybrid nanocomposites and CuO-CuO heterojunction positions along with the growth of GQDs on the core of CuO-CuO crystals. The electrochemical sensing performance of the as-fabricated CuO-CuO@GQD EHPs was monitored for the determination of bisphenol A (BPA) as an early diagnostic marker and environmental contaminant. The synergistic effects of the boosted surface area, exposed Cu {111} crystallographic planes and mixed copper valences enhance redox reaction kinetics by increasing the electron shuttling rate at the electrode-analyte junction. Benefitting from the improved electrocatalytic activity for BPA oxidation, the electrochemical sensor displayed the lowest limit of detection (≤1 nM), good chemical stability, a broad linear range (2 nM-11 mM), and high sensitivity (636 μA mM cm). The CuO-CuO@GQD EHP-based sensing platform was used for BPA detection in water and human serum samples. We have also constructed a pioneering electrochemical sensing platform for BPA detection in live cells, which might be used as a marker for early disease diagnosis.
晶面金属氧化物异质结构的发展由于其在纳米尺度上的合理设计和多功能特性而引起了极大的关注。在此，我们报告了一种简便的基于溶液的方法，用于合成单晶氧化铜纳米结构（即 CuO-CuO）作为核心。在室温下，通过自组装在乙醇溶液中在 CuO 扩展六足（EHPs）的表面上制造出具有不同浓度的石墨烯量子点（GQDs），其中铜既充当牺牲模板又充当稳定剂。CuO 晶体由于其高能面、悬空键和大量表面铜原子，对 BPA 氧化表现出良好的传感活性。详细进行了结构、形态、化学和振动研究，呈现出混合纳米复合材料的高结晶度以及 CuO-CuO 异质结位置以及 GQDs 在 CuO-CuO 晶体核心上的生长。监测了所制备的 CuO-CuO@GQD EHPs 的电化学传感性能，以作为早期诊断标志物和环境污染物来测定双酚 A（BPA）。通过增加电极-分析物界面处的电子穿梭速率，增强了表面面积、暴露的 Cu{111}晶面和混合铜价的协同效应，从而增强了氧化还原反应动力学。受益于对 BPA 氧化的改进的电催化活性，电化学传感器显示出最低的检测限（≤1 nM）、良好的化学稳定性、宽线性范围（2 nM-11 mM）和高灵敏度（636 μA mM cm）。基于 CuO-CuO@GQD EHP 的传感平台用于水和人血清样品中的 BPA 检测。我们还构建了用于活细胞中 BPA 检测的开创性电化学传感平台，该平台可用作早期疾病诊断的标志物。
