化学学报 ›› 2020, Vol. 78 ›› Issue (2): 147-154.DOI: 10.6023/A19090338 上一篇    下一篇

所属专题: 多孔材料:金属有机框架(MOF)

研究论文

基于RGO-Au-ZIF-8复合材料的电化学传感器制备及其在铅离子和铜离子同时检测中的应用

孙延慧a, 齐有啸a, 申优a, 井翠洁b, 陈笑笑a, 王新星b   

  1. a 青岛科技大学环境与安全工程学院 青岛 266042;
    b 青岛科技大学化学与分子工程学院 青岛 266042
  • 投稿日期:2019-09-12 发布日期:2020-01-10
  • 通讯作者: 孙延慧, 王新星 E-mail:sunyh@qust.edu.cn;wangxx@qust.edu.cn
  • 基金资助:
    项目受国家自然科学基金(No.21804076)、山东省自然科学基金(No.ZR2017BB040)、青岛市应用基础研究计划(No.17-1-1-65-jch)和光电传感与生命分析教育部重点实验室开放课题(No.SATM201708)资助.

Preparation of Electrochemical Sensor Based on RGO-Au-ZIF-8 Composite and Its Application in Simultaneous Detection of Lead Ions and Copper Ions

Sun Yanhuia, Qi Youxiaoa, Shen Youa, Jing Cuijieb, Chen Xiaoxiaoa, Wang Xinxingb   

  1. a College of Environmental and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042;
    b College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042
  • Received:2019-09-12 Published:2020-01-10
  • Supported by:
    Project supported by the National Natural Science Foundation of China (No. 21804076), the Natural Science Foundation of Shandong Province (No. ZR2017BB040), the Applied Basic Research Program of Qingdao (No. 17-1-1-65-jch) and the Open Fund of Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, Ministry of Education, Qingdao University of Science and Technology (No. SATM201708).

金属有机骨架(MOFs)材料因其结构和组成特点在重金属离子的吸附和预富集方面表现出独特优势,在重金属离子的光学传感方面显示出极大的应用潜力,但其导电性较差,这大大限制了其在电化学传感领域的应用.制备了一种功能化的金属有机骨架复合材料——热还原氧化石墨烯-金-沸石咪唑酯骨架材料(RGO-Au-ZIF-8).该复合材料具有较本体MOF显著改善的电化学性质,利用其构建电化学传感平台实现了对水相溶液中铅离子(Pb2+)和铜离子(Cu2+)的同时灵敏检测.借助扫描电子显微镜、透射电子显微镜、紫外可见吸收光谱法和各种电化学技术对所制备材料及其修饰电极的形貌、结构和电化学特性进行了表征.采用阳极溶出伏安法(DPASV)对水相溶液中的Pb2+和Cu2+进行检测,并对检测溶液pH、沉积时间和沉积电位等实验参数进行了优化.在最优化条件下,该传感平台对Pb2+和Cu2+的检测线性浓度范围分别为0.005~10(Pb2+)和0.01~10(Cu2+)μmol·L-1,检测限为2.6×10-9(Pb2+)和7.8×10-9(Cu2+) mol·L-1.此外,还对该传感平台的选择性、重现性和稳定性进行了考察,并进行了实际水样中Pb2+和Cu2+的回收实验.该工作为重金属离子的同时、快速且灵敏的检测提供了一种新的平台,并大大拓展了MOFs材料的电化学应用.

关键词: RGO-Au-ZIF-8, 电化学传感器, 同时检测, 铅离子, 铜离子

Metal organic frameworks (MOFs) have unique advantages in adsorption and preconcentration of heavy metal ions due to their structure and composition characteristics, which make them show great potential in optical sensing of heavy metal ions. However, their applications in the field of electrochemical sensing is greatly limited because of their poor conductivity. In this work, a functionalized MOF composite, thermally reduced graphene oxide-Au nanoparticles-zeolitic imidazolate skeleton material (RGO-Au-ZIF-8), was fabricated. It exhibits much improved electrochemical properties compared with the pristine MOF. A novel electrochemical sensing platform was constructed based on it, and simultaneous detection of lead ions (Pb2+) and copper ions (Cu2+) in aqueous solution was realized. Specifically, the Au-ZIF-8 was prepared by adding polyvinylpyrrolidone (PVP)-stabilized Au nanoparticles (AuNPs) to the reaction solution of ZIF-8. The modification of AuNPs effectively improved the conductivity of the material. After compounding with RGO, the RGO-Au-ZIF-8 composite was prepared. The RGO was used as scaffold for the Au-ZIF-8 in the composite to increase the effective surface area of electrode and improve conductivity. The morphology and structure of the prepared materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy (UV-Vis). The electrochemical properties of the modified electrodes were characterized by various electrochemical techniques. The experimental parameters, such as pH value of working solution, accumulation potential, accumulation time and composition ratio of Au-ZIF-8 to RGO were optimized. Under the optimized conditions, simultaneous and sensitive detection of Pb2+ and Cu2+ on the prepared electrochemical sensor was realized with the detection limits of 2.6×10-9 and 7.8×10-9 mol·L-1 for Pb2+ and Cu2+, respectively (S/N=3). The interference test showed that the electrochemical sensor has good selectivity for the detection of Pb2+ and Cu2+, and further electrochemical studies revealed that the designed sensor has excellent reproducibility and good stability. The result of recovery test indicated that the prepared electrochemical sensor has great potential in Pb2+ and Cu2+ detection in real water samples. This work provides a new platform for simultaneous, rapid and sensitive detection of heavy metal ions, and greatly expands the electrochemical applications of MOF materials.

Key words: reduced graphene oxide-Au nanoparticles-zeolitic imidazolate skeleton material (RGO-Au-ZIF-8), electrochemical sensor, simultaneous detection, lead ion, copper ion