Key Laboratory of Environmental Optics and Technology and Institute of Intelligent Machines , Chinese Academy of Sciences , Hefei 230031 , People's Republic of China.
University of Science and Technology of China , Hefei 230026 , People's Republic of China.
Anal Chem. 2018 Apr 3;90(7):4569-4577. doi: 10.1021/acs.analchem.7b04981. Epub 2018 Mar 23.
Developing a new ultrasensitive interface to detect As(III) is highly desirable because of its seriously toxic and low concentration in drinking water. Recently, FeO nanoparticles of high adsorption toward As(III) become very promising to be such an interface, which is still limited by the poor understanding of their surface physicochemical properties. Herein, we report that dumbbell-like Au/FeO nanoparticles, when being modified the screen-printed carbon electrode, can serve as an efficient sensing interface for As(III) detection with an excellent sensitivity of 9.43 μA ppb and a low detection limit of 0.0215 ppb. These outstanding records were attributed to the participation of Fe(II)/Fe(III) cycle on FeO surface in the electrochemical reaction of As(III) redox, as revealed by X-ray photoelectron spectroscopy, X-ray absorption near edge structure, and extended X-ray absorption fine structure. This work provides new insight into the mechanism of electroanalysis from the viewpoint of surface active atoms, and also helps to predict the construction of ultrahighly sensitive electrochemical sensors for other heavy metal ions with nonprecious redox active materials.
开发一种新的超灵敏界面来检测 As(III) 是非常理想的，因为它在饮用水中的毒性很强且浓度很低。最近，对 As(III) 具有高吸附能力的 FeO 纳米粒子作为这种界面具有很大的应用前景，但仍受到对其表面物理化学性质认识不足的限制。在此，我们报告哑铃状的 Au/FeO 纳米粒子在被修饰到丝网印刷碳电极上后，可以作为一种用于 As(III)检测的高效传感界面，其灵敏度为 9.43 μA ppb，检测限低至 0.0215 ppb。这些优异的记录归因于 Fe(II)/Fe(III) 循环在 FeO 表面上参与了 As(III)氧化还原的电化学反应，这一点通过 X 射线光电子能谱、X 射线吸收近边结构和扩展 X 射线吸收精细结构得到了揭示。这项工作从表面活性原子的角度提供了对电分析机制的新见解，并有助于预测使用非贵金属氧化还原活性材料构建用于其他重金属离子的超高灵敏电化学传感器。
