title: Surface plasmon resonance immunosensor for human cardiac troponin T based on self-assembled monolayer.
abstract: The cardiac troponin T (cTnT) is specific biomarker important for trials of acute myocardial infarctions (AMI). In this paper, a SPR sensor in real time to detect the biomarker was developed on a commercially available surface plasmon resonance AUTOLAB SPIRIT. The cTnT receptor molecule was covalently immobilized on a gold substrate via a self-assembled monolayer (SAM) of thiols by using cysteamine-coupling chemistry. This biosensor presented a linear response range for cTnT between 0.05 and 4.5 ng/mL (r=0.997, p<<0.01) with a good reproducibility (CV=4.4%). The effect of the cysteamine (CYS) concentrations on the SAM coated gold sensor was studied as a function of the amount of the immobilized cTnT monoclonal antibodies. Analysis using serum samples undiluted was carried out at room temperature showing a well agreement with the ECLIA methods and the sensor surface could be regenerated by using a solution of 1% (w/v) sodium dodecyl sulphate (SDS) without losing the sensor immunoreactivity. These studies open new perspectives of using SAM to develop regenerable immunosensor with a good reproducibility allowing its use in the clinical applications.
authors.affiliation: Departamento de Patologia, Instituto de Ciências Biológicas, Universidade de Pernambuco, Rua Arnóbio Marques, 310, Santo Amaro, 50100-130 Recife, PE, Brazil.
authors.forename: Rosa Fireman
authors.initials: RF
authors.lastname: Dutra
authors.forename: Renata Kelly
authors.initials: RK
authors.lastname: Mendes
authors.forename: Valdinete
authors.initials: V
authors.lastname: Lins da Silva
authors.forename: Lauro Tatsuo
authors.initials: LT
authors.lastname: Kubota
mesh_terms: D000327:Adsorption; D000911:Antibodies, Monoclonal / Q000276:immunology; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003543:Cysteamine / Q000737:chemistry; D005240:Feasibility Studies; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D007700:Kinetics; D008163:Luminescent Measurements; D015203:Reproducibility of Results; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods; D013696:Temperature; D020107:Troponin T / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D020099:Coated Materials, Biocompatible; D013438:Sulfhydryl Compounds; D020107:Troponin T; D003543:Cysteamine; D006046:Gold