化学学报 ›› 2023, Vol. 81 ›› Issue (8): 920-927.DOI: 10.6023/A23040170 上一篇    下一篇

所属专题: 庆祝《化学学报》创刊90周年合辑

研究论文

基于共价有机框架修饰电极的维生素A和C的选择性检测

杨蓉婕, 周璘*, 苏彬*()   

  1. 浙江大学化学系 杭州 310058
  • 投稿日期:2023-04-27 发布日期:2023-09-14
  • 作者简介:
    庆祝《化学学报》创刊90周年.
  • 基金资助:
    项目受国家自然科学基金(22125405); 项目受国家自然科学基金(22074131); 项目受国家自然科学基金(21874117); 国家重点研发计划(2019YFB2204903)

Selective Detection of Vitamins A and C based on Covalent Organic Framework Modified Electrodes

Rongjie Yang, Lin Zhou, Bin Su()   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310058
  • Received:2023-04-27 Published:2023-09-14
  • Contact: *E-mail: subin@zju.edu.cn
  • About author:
    Dedicated to the 90th anniversary of Acta Chimica Sinica.
  • Supported by:
    National Natural Science Foundation of China(22125405); National Natural Science Foundation of China(22074131); National Natural Science Foundation of China(21874117); National Key Research and Development Program of China(2019YFB2204903)

电极界面的设计与调控, 对于实现复杂样品中待测物质的准确分析具有重要意义. 用1,3,5-三(4-氨苯基)苯(TAPB)分别与对苯二甲醛(PDA)和溴取代对苯二甲醛(BrPDA)缩聚, 在液/液界面上制备了两种亲疏水性不同的共价有机框架(COF)膜, 并将其转移到氧化铟锡玻璃(ITO)电极上, 研究了疏水性的维生素A (VA)和亲水性的维生素C (VC)在两种COF修饰电极上的电化学响应. 结果显示, TAPB-BrPDA COF/ITO电极表面较为疏水, 在排阻VC的同时可对VA进行选择性的电化学检测, 线性范围为5~100 μmol/L, 检出限为1.32 μmol/L. 而TAPB-PDA COF/ITO电极则恰好相反, 可排阻VA而对VC有较好的选择性, 电化学检测的线性范围为5~200 μmol/L, 检出限为1.35 μmol/L. 因此, 两种电极可用于维生素复合片中VA和VC的定量测定, 回收率分别达到104%和101%.

关键词: 共价有机框架, 电化学分析, 维生素, 结构调控, 选择性

The engineering and regulation of electrode interfaces are of great significance for accurate analysis of specific analyte in complex samples. Covalent organic frameworks (COF), as a class of crystalline polymers formed precisely and periodically by building blocks, have provoked exponential interest due to their pre-designable and adjustable pore sizes, hydrophobicity, geometry and so on. Therefore, varying the structures of monomers is able to modulate the molecular permeability of COF and achieve selective detection of different analytes. In this work, the polycondensation reaction between the amine monomer, namely 1,3,5-tris(4-aminophenyl) benzene (TAPB), and two different aldehyde monomers, namely terephthalaldehyde (PDA) and 2,5-dibromoterephthalaldehyde (BrPDA), at the liquid/liquid interface was conducted to prepare continuous and uniform imine-linked covalent organic framework (COF) membranes. The membranes were subsequently transferred onto the surface of indium tin oxide (ITO) glass electrodes and then the electrochemical responses of hydrophobic vitamin A (VA) and hydrophilic vitamin C (VC) at two COF modified electrodes were investigated. Due to the existing of Br groups on the pore walls of TAPB-BrPDA COF, it is hydrophobic with a contact angle of 122°, while the TAPB-PDA COF membrane is hydrophilic with a contact angle of 73°. The electrochemical responses of two COF modified electrodes towards hydrophobic VA and hydrophilic VC were studied in 1 mol/L NaCl solution. The results of cyclic voltammetry revealed that TAPB-BrPDA COF could prohibit effectively the permeability of VC whereas allow that of VA, eventually achieving the selective electrochemical detection of the latter with a detection linear range of 5~100 μmol/L and a limit of detection at 1.32 μmol/L. In contrast, TAPB-PDA COF/ITO electrode can reject the access of VA whereas permit that of VC, thus showing good electrochemical selectivity toward VC and yielding a linear detection range of 5~200 μmol/L and a limit of detection at 1.35 μmol/L. Finally, two electrodes were successfully used for the quantitative determination of VA and VC in multivitamin tablets with recoveries of 104% and 101%, respectively. This work constitutes a step in the surface engineering of electrodes by COF to realize pre-designed composition and functions and thus excellent selectivity towards specific molecules.

Key words: covalent organic framework, electrochemical analysis, vitamin, structure control, selectivity