title: Nanoimmunoassay onto a screen printed electrode for HER2 breast cancer biomarker determination.
abstract: A chip format sandwich-type immunoassay based on Nanobodies(®) (Nbs) with the Human Epidermal Growth Factor Receptor (HER2) extracellular domain as antigen model has been developed. The HER2 is considered as an important biomarker because its overexpression causes an aggressive type of breast cancer. Nbs are single domain antigen-binding fragments derived from camelid heavy-chain antibodies. The strategy of the presently developed sandwich immunoassay takes advantage of the small size of Nbs for the detection of the electroactive redox tracer onto the screen printed electrode (SPE). A capture anti HER2 Nb was covalently immobilized onto the SPE, and the detection Nb, raised against another epitope of HER2, was labeled with horseradish peroxidase (HRP). The biosensor signal corresponded to the electroreduction of para-quinone generated at the SPE by the HRP in the presence of hydroquinone and hydrogen peroxide. The best performing and optimized immunoassay conditions consisted of 2 and 20 min for the first and the second incubation times, respectively. The amperometric signal obtained was proportional to the logarithm of HER2 concentration between 1 and 200 µg/mL and the modified SPE storage stability lasted for at least three weeks. Determination of HER2 in human cells has been realized.
authors.affiliation: Laboratory of Instrumental Analysis and Bioelectrochemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, Campus Plaine, CP 205/06, 1050 Brussels, Belgium. Electronic address: spatris@ulb.ac.be.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Patris
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Research Center, VIB, Vrije Universiteit Brussel, 1050 Brussels, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: De Pauw
authors.affiliation: Laboratory of Instrumental Analysis and Bioelectrochemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, Campus Plaine, CP 205/06, 1050 Brussels, Belgium.
authors.forename: Marie
authors.initials: M
authors.lastname: Vandeput
authors.affiliation: Laboratory of Biopolymers and Supramolecular Nanomaterials, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, Campus Plaine, CP 206/04, 1050 Brussels, Belgium.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Huet
authors.affiliation: Analytical Platform, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, Campus Plaine, CP 205/05, 1050 Brussels, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Antwerpen
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Structural Biology Research Center, VIB, Vrije Universiteit Brussel, 1050 Brussels, Belgium.
authors.forename: Serge
authors.initials: S
authors.lastname: Muyldermans
authors.affiliation: Laboratory of Instrumental Analysis and Bioelectrochemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, Campus Plaine, CP 205/06, 1050 Brussels, Belgium. Electronic address: jmkauf@ulb.ac.be.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Kauffmann
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015374:Biosensing Techniques; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D061986:MCF-7 Cells; D036103:Nanotechnology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis* / Q000737:chemistry; D061905:Single-Domain Antibodies / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D014408:Biomarkers, Tumor; D006735:Horseradish Peroxidase; D006861:Hydrogen Peroxide; D018719:Erb-b2 Receptor Tyrosine Kinases; D061905:Single-Domain Antibodies; C508053:ERBB2 protein, human
keywords: Amperometric immunosensor; HER2; Immunoassay; Nanobody; Screen printed electrode