%0 Journal Article %@ 0956-5663 %A Wang, SX %A Acha, D %A Shah, AJ %A Hills, F %A Roitt, I %A Demosthenous, A %A Bayford, RH %D 2017 %F discovery:1527523 %J Biosensors and Bioelectronics %K Alzheimer's disease; Biomarker; Electrochemical biosensor; Impedance; Tau %P 482-488 %T Detection of the tau protein in human serum by a sensitive four-electrode electrochemical biosensor %U https://discovery.ucl.ac.uk/id/eprint/1527523/ %V 92 %X This study presents a novel approach based on a four-electrode electrochemical biosensor for the detection of tau protein – one of the possible markers for the prediction of Alzheimer's disease (AD). The biosensor is based on the formation of stable antibody–antigen complexes on gold microband electrodes covered with a layer of a self-assembled monolayer and protein G. Antibodies were immobilized on the gold electrode surface in an optimal orientation by protein G interaction. Electrochemical impedance spectroscopy was used to analyze impedance change, which revealed a linear response with increasing tau concentrations. The assay is fast (<1 h for incubation and measurement) and very sensitive. The limit of quantification for the full-length 2N4R tau protein is 0.03 pM, a value unaltered when the assay was processed in bovine serum albumin or human serum. This technology could be adapted for the detection of other biomarkers to provide a multiple assay to identify AD progression in a point of care setting. %Z Copyright © 2016. This manuscript version is published under a Creative Commons Attribution Non-commercial Non-derivative 4.0 International licence (CC BY-NC-ND 4.0). This licence allows you to share, copy, distribute and transmit the work for personal and non-commercial use providing author and publisher attribution is clearly stated. Further details about CC BY licences are available at http://creativecommons.org/licenses/by/4.0. Access may be initially restricted by the publisher.