Dai Xingxin, Qiu Fagui, Zhou Xuan, Long Yumei, Li Weifeng, Tu Yifeng
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, PR China.
Department of Quartermaster Engineering, Jilin University, No. 5333, Xi'an Road, Changchun 130062, PR China.
Anal Chim Acta. 2014 Oct 27;848:25-31. doi: 10.1016/j.aca.2014.08.002. Epub 2014 Aug 13.
This paper described a facile and direct electrochemical method for the determination of ultra-trace Cu(2+) by employing amino-functionalized mesoporous silica (NH2-MCM-41) as enhanced sensing platform. NH2-MCM-41 was prepared by using a post-grafting process and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and fourier transform infrared (FTIR) spectroscopy. NH2-MCM-41 modified glassy carbon (GC) electrode showed higher sensitivity for anodic stripping voltammetric (ASV) detection of Cu(2+) than that of MCM-41 modified one. The high sensitivity was attributed to synergistic effect between MCM-41 and amino-group, in which the high surface area and special mesoporous morphology of MCM-41 can cause strong physical absorption, and amino-groups are able to chelate copper ions. Some important parameters influencing the sensor response were optimized. Under optimum experimental conditions the sensor linearly responded to Cu(2+) concentration in the range from 5 to 1000 ng L(-1) with a detection limit of 0.9 ng L(-1) (S/N=3). Moreover, the sensor possessed good stability and electrode renewability. In the end, the proposed sensor was applied for determining Cu(2+) in real samples and the accuracy of the results were comparable to those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) method.
本文描述了一种简便直接的电化学方法，该方法通过使用氨基功能化介孔二氧化硅（NH2-MCM-41）作为增强传感平台来测定超痕量铜离子（Cu(2+)）。NH2-MCM-41采用后接枝工艺制备，并通过X射线衍射（XRD）、透射电子显微镜（TEM）和傅里叶变换红外（FTIR）光谱进行表征。与MCM-41修饰的玻碳（GC）电极相比，NH2-MCM-41修饰的GC电极对阳极溶出伏安法（ASV）检测Cu(2+)具有更高的灵敏度。高灵敏度归因于MCM-41与氨基之间的协同效应，其中MCM-41的高比表面积和特殊的介孔形态可引起强烈的物理吸附，而氨基能够螯合铜离子。优化了一些影响传感器响应的重要参数。在最佳实验条件下，该传感器对Cu(2+)浓度在5至1000 ng L(-1)范围内呈线性响应，检测限为0.9 ng L(-1)（S/N = 3）。此外，该传感器具有良好的稳定性和电极可更新性。最后，将所提出的传感器应用于实际样品中Cu(2+)的测定，结果的准确性与电感耦合等离子体发射光谱法（ICP-OES）获得的结果相当。
