Antibody-functionalised gold nanoparticles-based impedimetric immunosensor: detection methods for better sensitivity

Micro & nano letters

article

Nadra Bohli¹  Meryem Belkilani¹  Laurence Mora³  Adnane Abdelghani¹ 

[1] Carthage University, National Institute of Applied Science and Technology, Research Unit of Nanobiotechnology and Valorisation of Medicinal Plants UR17ES22, Centre Urbain Nord;Tunis University;Université Paris13, Institut Galilée

关键词: nanoparticles;    gold;    biosensors;    electrochemical sensors;    electric impedance measurement;    antibody-functionalised gold nanoparticles-based impedimetric immunosensor;    electrochemical immunosensors;    immunosensors properties;    glycated human serum albumin;    layer-by-layer system;    sandwich system;    analyte detection;    antibody detection;    bioreceptor;    steric hindrance effect;    Au;   

DOI  :  10.1049/mnl.2018.5587

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Electrochemical immunosensors are generally layer-by-layer or sandwich systems designed to detect an analyte in a solution. Immunosensors are mainly based on the high affinity and specificity of the antibody towards its antigen. This work aims to answer the following question: if we ‘flip’ the immunosensor and build it backwards, thus detecting the antibody with the antigen instead of detecting the antigen with the antibody, will we obtain the same immunosensors properties or not? To answer this question, they tested a system composed of glycated human serum albumin and antibody-functionalised gold nanoparticles. Impedance spectrum results showed a difference in both the sensitivity and linear range of the built impedimetric immunosensors. The sensitivity of the sensor using the antibody as a bioreceptor was approximated to 0.32 [%. [% (Glycated to total albumin])] − 1] against a sensitivity of 0.80 [%. [% (Glycated to total albumin])] − 1] for the ‘upside-down’ sensor, using the antigen as a bioreceptor. This study observed also a shift to high glycation levels in the linear range of the upside-down sensor. These differences could be explained by the effect of steric hindrance and a higher degree of freedom allowing better characteristics for the upside-down immunosensor.

【 授权许可】

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