Authors: Sheila A Grant Mary E Pierce Darcy J Lichlyter David A Grant
Publish Date: 2005/02/05
Volume: 381, Issue: 5, Pages: 1012-1018
Abstract
A novel optical biosensor technique is being developed for the early detection of myocardial infarction by utilizing the distancedependent chemical transduction method of fluorescence resonance energy transfer FRET The FRET process requires two fluorophores termed the donor and the acceptor When in close proximity the donor absorbs energy from the excitation source and nonradiatively transfers the energy to the acceptor which in turn emits fluorescent energy This distancedependent property was utilized to detect conformational changes when antibodies combine with their respective antigens The fluorophores were conjugated to an antibody–Protein A complex and then immobilized via silanization to the distal ends of optical fibers Three different antibody–Protein A complexes were immobilized generic IgG cardiac Troponin T cTnT and cardiac Troponin I cTnI Results showed that upon the addition of the specific antigens the antibodies underwent a conformational change reducing the distance between the FRET fluorophores The generic IgG responded to 233 nM antigens whereas the cTnT biosensor had a limit of detection of 75 nM and the cTnI biosensors had a limit of detection of 94 nM
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