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  

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

作　　者：杨蓉婕 周璘 苏彬[1] Yang Rongjie;Zhou Lin;Su Bin(Department of Chemistry,Zhejiang University,Hangzhou 310058)

机构地区：[1]浙江大学化学系,杭州310058

出　　处：《化学学报》2023年第8期920-927,共8页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.22125405,22074131,21874117);国家重点研发计划(No.2019YFB2204903)资助。

摘　　要：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5~100μmol/L,检出限为1.32μmol/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5~200μmol/L,检出限为1.35μmol/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%.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 5~100μmol/L and a limit of detection at 1.32μmol/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 5~200μmol/L and a limit of detection at 1.35μmol/L.Finally,two electrodes were suc

关 键 词：共价有机框架 电化学分析 维生素 结构调控 选择性 

分 类 号：TQ466[化学工程—制药化工] O657.1[理学—分析化学]