title: Piezoelectric biosensors for biorecognition analysis: application to the kinetic study of HIV-1 Vif protein binding to recombinant antibodies.
abstract: In this work three piezoelectric sensors modified with anti-HIV-1 Vif (virion infectivity factor) single fragment antibodies (4BL scFV), single domains (VH) and camelized single domains (VHD) were constructed and used to detect HIV1 Vif in liquid samples. Dithio-bis-succinimidyl-undecanoate (DSU) and 11-hydroxy-1-undecanethiol (HUT) mixed self assembled monolayers (SAM) were generated at the sensors surface onto which the antibodies were immobilized. All sensors detected specifically the target HIV1-Vif antigen in solution and no unspecific binding was monitored. Impedance analysis was performed to quantify electroacoustic and viscoelastic interferences during antibody immobilization and antigen recognition. The elimination of such interferences enabled the quantitative use of the piezoelectric immunosensors to estimate the antibody surface density as well as antigen binding and equilibrium constants. In spite of the possible limitation regarding mass transport and other related molecular phenomena, which were not considered in the binding model used, this work demonstrates the usefulness of piezoelectric biosensors in biorecognition analysis and evidences the advantages on using simultaneous impedance analysis to bring analytical significance to measured data, and thus to improve piezoelectric sensors sensitivity and applicability.
authors.affiliation: Institute for Biotechnology and Bioengineering (IBB), Centro de Biomedicina Molecular e Estrutural, Universidade do Algarve, 8000 Faro, Portugal.
authors.forename: João M
authors.initials: JM
authors.lastname: Encarnação
authors.forename: Luis
authors.initials: L
authors.lastname: Rosa
authors.forename: Rogério
authors.initials: R
authors.lastname: Rodrigues
authors.forename: Luisa
authors.initials: L
authors.lastname: Pedro
authors.forename: Frederico Aires
authors.initials: FA
authors.lastname: da Silva
authors.forename: João
authors.initials: J
authors.lastname: Gonçalves
authors.forename: Guilherme N M
authors.initials: GN
authors.lastname: Ferreira
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation; D015483:HIV Antibodies; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D015336:Molecular Probe Techniques / Q000295:instrumentation; D011791:Quartz / Q000737:chemistry; D011994:Recombinant Proteins / Q000378:metabolism; D054320:vif Gene Products, Human Immunodeficiency Virus / Q000032:analysis* / Q000276:immunology
chemical_list: D015483:HIV Antibodies; D011994:Recombinant Proteins; D054320:vif Gene Products, Human Immunodeficiency Virus; C514847:vif protein, Human immunodeficiency virus 1; D011791:Quartz