AVS 49th International Symposium
    Biomaterials Tuesday Sessions
       Session BI+SS-TuA

Paper BI+SS-TuA8
Electrostatic and Fluorescence Sensing of DNA Hybridization at Electrode Surfaces

Tuesday, November 5, 2002, 4:20 pm, Room C-201

Session: Molecular Recognition Surfaces
Presenter: R.M. Georgiadis, Boston University
Authors: R.M. Georgiadis, Boston University
J. Wang, Boston University
L.K. Wolf, Boston University
A.W. Peterson, Boston University
Correspondent: Click to Email
Current microarray technologies, based on specific probe-target hybridizations, often suffer from nonspecific surface interactions. In addition, for surface immobilized probes, thermodynamic equilibrium conditions may not be reached without excessively long incubation times and hybridization may be kinetically or sterically inaccessible for some probe sequences or for some surface probe densities. In previous work on perfectly matched duplexes, we have shown that probe density is a controlling factor for DNA hybridization at surfaces. Here, we expand our studies to investigate probe density effects for mismatched sequence or targets that access different binding locations on the immobilized probe. To improve mismatched hybrid discrimination we detect different dissociation profiles for matched and mismatched 25-mer targets from surface-immobilized probes in the presence of an applied repulsive electrostatic field and present denaturation profiles for surface-bound hybrids obtained by continuously varying the applied electrostatic surface field. Finally, we examine the immobilization and hybridization of covalently-bound molecular beacons on gold surfaces using surface plasmon resonance (SPR) spectroscopy and fluorescence spectroscopy.