基于抑制壳聚糖-金纳米材料类酶活性的半胱氨酸检测  

Detection of L-cysteine Based on Inhibition of Peroxidase-like Activity of Chitosan-AuNPs

作　　者：姜翠凤[1] 李卓健 朱洵 夏浩浩 徒华健 JIANG Cuifeng;LI Zhuojian;ZHU Xun;XIA Haohao;TU Huajian(School of Materials Science and Engineering,Yancheng Institute of Technology,Yancheng 224051)

机构地区：[1]盐城工学院材料科学与工程学院,江苏盐城224051

出　　处：《分析科学学报》2020年第4期523-527,共5页Journal of Analytical Science

基　　金：国家自然科学基金(No.21605128);盐城工学院人才引进启动项目(No.xj201530)。

摘　　要：基于L-半胱氨酸(L-Cysteine)对壳聚糖-金纳米粒子(CS-AuNPs)过氧化物酶样活性的抑制,构建了一种新型、简单和灵敏的半胱氨酸传感器。CS-AuNPs具有过氧化物酶样活性,表现为在H 2 O 2存在下,能够使3,3′,5,5′-四甲基联苯胺(TMB)发生氧化生成蓝色产物。半胱氨酸能明显抑制其活性,加入半胱氨酸后,体系颜色变浅,在波长652 nm处吸收值降低。利用过氧化物酶样活性的降低,设计了一种灵敏度高、选择性好的检测半胱氨酸的比色传感器。结合紫外-可见吸收光谱,检测限低至0.4μmol/L,低于细胞中半胱氨酸的正常水平(30~200μmol/L)。讨论了半胱氨酸抑制催化活性的机理。该传感器具有无需修饰、检测步骤少、肉眼观察方便等优点,在分析和生物技术领域具有潜在的应用价值。A simple and sensitive L-cysteine sensor was developed based on inhibition of peroxidase-like activity of chitosan-Au nanoparticles(CS-AuNPs).CS-AuNPs was found to possess peroxidase-like activity by catalyzing 3,3′,5,5′-tetramethylbenzidine to produce blue product.The activity could be distinctly inhibited by cysteine evidenced by lighter color and decreased absorbance at 652 nm.The decrease of peroxidase-like activity was applied to develop a sensitive and selective colorimetric sensor for the detection of cysteine.Coupled with absorption spectra,a limit of detection can be obtained as low as 0.4μmol/L,which is below the normal level of cysteine in cells(30-200μmol/L).The mechanism accounting for the suppression of catalytic ability was discussed.Considering the advantages of label-free,minimized detecting steps and naked-eye observation,this smart sensor exhibits potential application for detection of cysteine in field of biotechnology.

关 键 词：壳聚糖-金纳米颗粒 L-半胱氨酸 过氧化物酶样活性 传感器 

分 类 号：O657.32[理学—分析化学]