An SPR immunosensor for human cardiac troponin T using specific binding avidin to biotin at carboxymethyldextran-modified gold chip

Background: The cardiac troponin T (TnT) is a cardiospecific, highly sensitive marker for myocardial damage and is immediately released to bloodstream during the acute myocardial infarction (AMI). Surface plasmon resonance (SPR) immunosensor was developed for the quick detection of human cTnT in real time. Methods: An SPR sensor streptavidin terminated self-assembled monolayer, which was used to binding biotinylated anti troponin T monoclonal antibodies, was developed. Results: The cTnT was determined from successive injections with a linear range from 0.03 up to 6.5 ng/ml. The detection limit was 0.01 ng/ml corresponding to a resonant angle change of 1.28 millidegrees. The system presented a good repeatability with 3.4% of variation between run after regeneration of the coated surface with a solution of 1% SDS. The effects of blocking of non-specific adsorption using different solutions were studied. It was possible to measure the cTnT without dilution of the human serum with good specificity and reproducibility. Conclusion: This sensor is practical and offer quick response in interval of 800 s. (c) 2006 Elsevier B.V. All rights reserved.