高等学校化学学报 ›› 2020, Vol. 41 ›› Issue (4): 706-715.doi: 10.7503/cjcu20190584

• 分析化学 • 上一篇    下一篇

环糊精基阻抗型传感器的制备及对L-半胱氨酸的识别

付可飞,连惠婷,魏晓峰,孙向英,刘斌()   

  1. 华侨大学材料科学与工程学院, 分子设计与绿色转化福建省高校重点实验室, 厦门 361021
  • 收稿日期:2019-11-11 出版日期:2020-04-10 发布日期:2020-01-10
  • 通讯作者: 刘斌 E-mail:bliu@hqu.edu.cn
  • 基金资助:
    国家自然科学基金(21575044);福建省自然科学基金(2015J01054, 2016J01062);福建省石墨烯粉体及复合材料工程技术研究中心建设项目(No.2017H2001)

Construction of Cyclodextrin-based Impedance Sensor for Recognition of L-Cysteine

FU Kefei,LIAN Huiting,WEI Xiaofeng,SUN Xiangying,LIU Bin()   

  1. College of Materials Science and Engineering, Key Laboratory of Molecular Designing and Green Conversions(Fujian University), Huaqiao University, Xiamen 361021, China
  • Received:2019-11-11 Online:2020-04-10 Published:2020-01-10
  • Contact: Bin LIU E-mail:bliu@hqu.edu.cn
  • Supported by:
    † Supported by the National Natural Foundation of China(21575044);the Natural Foundation of Fujian Province, China(2015J01054, 2016J01062);the Foundation of Graphene Powder & Composite Research Center of Fujian Province, China(No.2017H2001)

摘要:

借助量子化学计算, 从分子层面模拟了γ-环糊精(γ-CD)主体与L-半胱氨酸(L-Cys)氧化产物客体之间的超分子相互作用, 得到γ-CD与L-Cys氧化产物之间的弱相互作用能EL(-12.6 eV), 其与D-Cys氧化产物客体的弱相互作用能(ED=-2.7 eV)相差3.7倍, 分子内氢键键价相差近1倍. 据此, 构建了基于手性源γ-环糊精的阻抗型传感器, 并用于L-Cys的阻抗识别. 结果表明, 以铁氰化钾(Ⅱ/Ⅲ)作为氧化还原探针分子, 电化学阻抗信号变量(Ret)与L-Cys浓度在0.1~1.0 μmol/L(阶段一)和1.0~6.0 μmol/L(阶段二)2个范围内分别呈现良好的线性关系, 检出限为74 nmol/L(S/N=3). 与未修饰玻碳电极相比, L-Cys在该手性传感器上的阻抗响应灵敏度提高了约19倍, 对含巯基结构相似物的选择性明显提高; 将该传感器应用于人体血清、 药品胶囊样品的分析, 平均回收率在88.9%~108%之间. 建立了一种新颖、 低成本、 简便的针对弱电活性手性化合物的定量识别方法, 为其电化学分析提供了新策略.

关键词: L-半胱氨酸, 阻抗识别, 电化学传感器, 环糊精, 电沉积传感

Abstract:

By means of quantum chemical calculation, the supramolecular interaction between the γ-cyclodextrin(γ-CD) as the host and the L-cysteine(L-Cys) oxidation product as the guest was simulated from the molecular level. The weak interaction energy(EL) between γ-CD and L-Cys oxidation product reaches -12.6 eV, which is 3.7 times different from the interaction between γ-CD and D-Cys oxidation product(ED=-2.7 eV). Their intramolecular hydrogen bonds exist nearly doubled difference. Based on the theoretical simulation, an γ-CD modified impedance sensor was constructed for sensitive and specific impedance identification of L-Cys. Using potassium ferricyanide(Ⅱ/Ⅲ) as the redox probe, the electrochemical transfer impedance(Ret) linearly changed with the concentration of L-Cys between 0.1 μmol/L and 1.0 μmol/L(stage one), and from 1.0 μmol/L and 6.0 μmol/L(stage two), with the detection limit of 74 nmol/L(S/N=3). Compared with the unmodified glassy carbon electrode, the sensitivity for the impedance response of L-Cys has been increased about 19 times. Meanwhile, the selectivity to the thiol-containing structural analog is significantly improved by this cyclodextrin-based sensor, successfully applied for the detection in human serum and drug capsules with average recoveries between 88.9% and 108%. This study establishes a novel, low-cost, simple, quantitative identification method for chiral compounds with weak electrical property, providing a potential strategy for electrochemical analysis of chiral targets.

Key words: L-Cysteine, Impedance recognition, Electrochemical sensor, Cyclodextrin, Electrodeposition sensing

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