IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Monday Sessions
       Session BI-MoM

Paper BI-MoM6
Probe Density Effects for Target Hybridization in DNA Monolayer Films Studied By SPR

Monday, October 29, 2001, 11:20 am, Room 102

Session: Molecular Recognition
Presenter: A.W. Peterson, Boston University
Authors: A.W. Peterson, Boston University
R.J. Heaton, Boston University
L.K. Wolf, Boston University
R.M. Georgiadis, Boston University
Correspondent: Click to Email
Understanding probe to target interactions for surface immobilized duplexes is important in the emerging applications of DNA biosensors. We use in-situ surface plasmon resonance spectroscopy to monitor the kinetics of probe immobilization and target/probe hybridization for thiol-modified probes immobilized on gold. We find that both the efficiency and kinetics of probe/target hybridization depend strongly on probe density. Immobilization conditions can be used to control probe density and we investigate the effects of solution ionic strength, electrostatic potential at the interface and whether duplex or single stranded probes are immobilized. Independent of which immobilization strategy is used, we find that DNA films of equal probe density exhibit reproducible efficiencies and kinetics for probe/target hybridization. In addition, the hybridization isotherms show a distinct dependence on probe density. Insight into the mechanism of these probe/target interactions are investigated and discussed in the context of the observed kinetics.