Acta Chimica Sinica ›› 2023, Vol. 81 ›› Issue (8): 920-927.DOI: 10.6023/A23040170 Previous Articles     Next Articles



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:
  • 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:
  • 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)

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