title: Characterization of a modified gold platform for the development of a label-free anti-thrombin aptasensor.
abstract: This work reports the characterization of a modified gold surface as a platform for the development of a label free aptasensor for thrombin detection. The biorecognition platform was obtained by the self-assembly of 4-mercaptobenzoic acid onto a gold surface, covalent attachment of streptavidin and further immobilization of the biotinylated anti-thrombin aptamer. The biosensing platform was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation monitoring. The biorecognition event aptamer-thrombin was detected from changes in the SPR angle produced as a consequence of the molecular interaction between the aptasensor and the target protein. The biosensing platform demonstrated to be highly selective for human thrombin even in the presence of large excess of bovine thrombin, bovine serum albumin, cytochrome C, lysozyme and myoglobin. The relationship between the changes in the SPR angle and thrombin concentration was linear up to 0.19 μmol L(-1) (R(2)=0.992) while the detection limit was of 12.0 nmol L(-1) (240 fmol in the sample). This new sensing approach represents an interesting and promising alternative for the SPR-based quantification of thrombin.
authors.affiliation: Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) CONICET-UNC, Departamento de Físico Química, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
authors.forename: Yamile
authors.initials: Y
authors.lastname: Jalit
authors.forename: Fabiana A
authors.initials: FA
authors.lastname: Gutierrez
authors.forename: Galina
authors.initials: G
authors.lastname: Dubacheva
authors.forename: Cedric
authors.initials: C
authors.lastname: Goyer
authors.forename: Liliane
authors.initials: L
authors.lastname: Coche-Guerente
authors.forename: Eric
authors.initials: E
authors.lastname: Defrancq
authors.forename: Pierre
authors.initials: P
authors.lastname: Labbé
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Rivas
authors.forename: Marcela C
authors.initials: MC
authors.lastname: Rodríguez
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001780:Blood Coagulation Tests / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013917:Thrombin / Q000032:analysis* / Q000037:antagonists & inhibitors
chemical_list: D052157:Aptamers, Nucleotide; D013917:Thrombin