PDF(Pubmed)
Abstract：
Pollution by heavy metal ions has a serious impact on human health and the environment, which is why the monitoring of heavy metal ions is of great practical importance. In this work, we describe the development of an electrochemical sensor for the detection of cadmium (Cd2+) involving the doping of porous SiO2 spheres with ZnO nanoparticles. Zinc oxide is chosen as the central dopant in the composite material to increase the conductivity and thus improve the electrochemical detection of Cd2+ ions with the SiO2 spheres. The resulting composite is characterized by electrochemical spectroscopic XRD and microscopic methods. As a result, the developed sensor shows good selectivity towards the targeted Cd2+ ions compared to other divalent ions. After optimization of the experimental conditions, the electrochemical sensor shows two different linear ranges between 2.5 × 10-11 molL-1 to 1.75 × 10-10 molL-1 and 2 × 10-9 molL-1 to 1.75 × 10-9 molL-1, indicating a change from diffusion-controlled to surface-controlled oxidation of Cd2+. A detection limit was reached at 4.4 × 10-11 molL-1. In addition, it offers good repeatability and recovery, and can detect accurate trace amounts of Cd2+ ions in real samples such as tap water or seawater by spiking these samples with known Cd2+ concentrations. This setup also provides satisfactory recovery rates in the range of 89-102%.
摘要：
重金属离子污染严重影响人类健康和环境,这就是为什么重金属离子的监测具有重要的现实意义。在这项工作中,我们描述了用于检测镉（Cd2）的电化学传感器的开发，该传感器涉及用ZnO纳米颗粒掺杂多孔SiO2球。选择氧化锌作为复合材料中的中心掺杂剂,以增加电导率,从而改善SiO2球体对Cd2+离子的电化学检测。通过电化学光谱XRD和微观方法对所得复合材料进行了表征。因此,与其他二价离子相比，开发的传感器对目标Cd2离子显示出良好的选择性。优化实验条件后,电化学传感器在2.5×10-11molL-1至1.75×10-10molL-1和2×10-9molL-1至1.75×10-9molL-1之间显示出两个不同的线性范围。从扩散控制到表面控制的Cd2氧化。检测限为4.4×10-11molL-1。此外,它提供了良好的可重复性和回收率，并且可以通过在自来水或海水等实际样品中添加已知的Cd2浓度来检测准确的痕量Cd2离子。该设置还提供89-102%范围内的令人满意的回收率。
