Electrochemical immunosensor for the milk allergen β-lactoglobulin based on electrografting of organic film on graphene modified screen-printed carbon electrodes
Electrochemical immunosensor for the milk allergen β-lactoglobulin based on electrografting of organic film on graphene modified screen-printed carbon electrodes
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DOI：
10.1016/j.bios.2012.06.008
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发表时间：
2012-10-01
影响因子：
12.6
通讯作者：
Zourob, Mohammed
中科院分区：
文献类型：
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作者：
Eissa, Shimaa;Tlili, Chaker;Zourob, Mohammed
利用石墨烯修饰的丝网印刷电极制备了一种新型的无标记伏安免疫传感器，用于β-乳球蛋白的灵敏检测。石墨烯电极表面的衍生化是通过在酸性水溶液中原位生成的4-硝基苯基重氮阳离子的电化学还原，然后将末端硝基电化学还原为胺来实现的。优化电化学修饰方案，以便在石墨烯表面上产生硝基苯基的单层，而不完全钝化电极。与报道的石墨烯功能化方法不同，我们在这里证明了芳基重氮盐的电接枝能够通过选择合适的接枝方案以受控方式将有机膜附着到石墨烯表面。接下来，使用戊二醛活化石墨烯表面上的胺基，并用于β-乳球蛋白抗体的共价固定。在含有[Fe（CN）（6）]（3-/4-）氧化还原对的水溶液中进行的循环和差分脉冲伏安法已被用于免疫传感器表征。结果表明，由于在修饰电极表面形成了抗体-抗原复合物，[Fe（CN）（6）]（3-/4-）的DPV还原峰电流随β-乳球蛋白浓度的增加而线性降低。使用这种新方法获得的免疫传感器能够在PBS缓冲液中实现0.85 pg mL（-1）的检测限和1 pg mL（-1）至100 ng mL（-1）的β-乳球蛋白的动态范围。此外，免疫传感器在不同的样品，包括蛋糕，奶酪小吃，甜饼干，表现出良好的相关性从商业酶联免疫吸附测定（ELISA）方法获得的结果进行了评估。(C)2012爱思唯尔有限公司版权所有。
A novel label-free voltammetric immunosensor for sensitive detection of beta-lactoglobulin using graphene modified screen printed electrodes has been developed. The derivatization of the graphene electrode surface was achieved by electrochemical reduction of in situ generated 4-nitrophenyl diazonium cations in aqueous acidic solution, followed by electrochemical reduction of the terminal nitro groups to amines. The electrochemical modification protocol was optimized in order to generate monolayer of nitrophenyl groups on the graphene surface without complete passivation of the electrode. Unlike the reported method for graphene functionalization, we demonstrated here the ability of the electrografting of aryl diazonium salt to attach an organic film to the graphene surface in a controlled manner by choosing the suitable grafting protocol. Next, the amine groups on the graphene surface were activated using glutaraldehyde and used for the covalent immobilization of beta-lactoglobulin antibodies. Cyclic and differential pulse voltammetry carried out in an aqueous solution containing [Fe(CN)(6)](3-/4-) redox pair have been used for the immunosensor characterization. The results demonstrated that the DPV reduction peak current of [Fe(CN)(6)](3-/4-) decreased linearly with increasing the concentration of beta-lactoglobulin due to the formation of antibody-antigen complex on the modified electrode surface. The immunosensor obtained using this novel approach enabled a detection limit of 0.85 pg mL(-1) and a dynamic range from 1 pg mL(-1) to 100 ng mL(-1) of beta-lactoglobulin in PBS buffer. In addition, the immunosensor evaluated in different samples including cake, cheese snacks, a sweet biscuit, showing excellent correlation with the results obtained from commercially enzyme-linked immunosorbent assay (ELISA) method. (C) 2012 Elsevier B.V. All rights reserved.