Detection of the tau protein in human serum by a sensitive four-electrode electrochemical biosensor.
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 (<1h for incubation and measurement) and very sensitive. The limit of quantification for the full-length 2N4R tau protein is 0.03pM, 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.
Department of Natural Sciences, Middlesex University, UK.
Scarlet Xiaoyan
SX
Wang
Department of Natural Sciences, Middlesex University, UK.
Desiree
D
Acha
Department of Natural Sciences, Middlesex University, UK.
Ajit J
AJ
Shah
Department of Natural Sciences, Middlesex University, UK.
Frank
F
Hills
Department of Natural Sciences, Middlesex University, UK.
Ivan
I
Roitt
Department of Electronic and Electrical Engineering, University College London, UK.
Andreas
A
Demosthenous
Department of Natural Sciences, Middlesex University, UK. Electronic address: r.bayford@mdx.ac.uk.
Richard H
RH
Bayford
D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D057230:Limit of Detection; D016875:tau Proteins / Q000097:blood*
D055910:Antibodies, Immobilized; D016875:tau Proteins; D006046:Gold
Alzheimer's disease; Biomarker; Electrochemical biosensor; Impedance; Tau