title: Comparison of the specificity and affinity of surface immobilised Affimer binders using the quartz crystal microbalance.
abstract: To enable multiplexed protein analysis through the use of microarrays, reliable molecules capable of specifically binding to a protein of interest with high affinity are required. Further, this specificity and affinity must be retained upon immobilization to the microarray surface. This study investigates the performance of surface bound Affimer proteins, comparing the affinity and specificity of different binders for closely related immunoglobulin molecules using the quartz crystal microbalance with dissipation monitoring (QCM-D). It is demonstrated that the surface bound Affimer proteins are highly specific, differentiating between their target IgG and other closely related IgG subclasses. The binding affinities of the protein aptamers for their target IgG molecules are determined to be in the nanomolar range, comparable to typical antibody-antigen binding affinities. While measurements herein are done using QCM-D, the high specificity and binding affinities of the surface bound Affimer proteins opens applications in a range of microarray biosensors.
authors.affiliation: Nanoscience Centre, University of Cambridge, 11 JJ Thomson Avenue, Cambridge CB3 0FF, UK. aas41@cam.ac.uk.
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Weckman
authors.affiliation: Avacta Life Sciences, Unit 651, Street 5, Thorp Arch Estate, Wetherby LS23 7FZ, UK.
authors.forename: Cassey
authors.initials: C
authors.lastname: McRae
authors.affiliation: Avacta Life Sciences, Unit 651, Street 5, Thorp Arch Estate, Wetherby LS23 7FZ, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Ko Ferrigno
authors.affiliation: Nanoscience Centre, University of Cambridge, 11 JJ Thomson Avenue, Cambridge CB3 0FF, UK. aas41@cam.ac.uk and Department of Engineering, Trumpington Street, Cambridge CB2 1PZ, UK.
authors.forename: Ashwin A
authors.initials: AA
authors.lastname: Seshia
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D055767:Immobilized Proteins / Q000737:chemistry*; D007074:Immunoglobulin G / Q000032:analysis*; D051379:Mice; D058525:Quartz Crystal Microbalance Techniques; D012680:Sensitivity and Specificity
chemical_list: D055767:Immobilized Proteins; D007074:Immunoglobulin G