Speaker: Dmitri Petrovykh, Department of Physics, University of Maryland, College Park, MD, Naval Research Laboratory, Washington, DC
Date & Time: December 11, 2008 - 12:00pm
Location: Chem. 260
Quantitative Characterization and Rational Design of DNA Biointerfaces
Laboratory for Surface Modification
Dmitri Petrovykh, Department of Physics, University of Maryland, College Park, MD,
Naval Research Laboratory, Washington, DC
12:00 Noon, Chem. 260
A promising pathway to the rational design of biointerfaces is suggested by the successful development of self-assembled monolayers (SAMs). The initial focus is placed on investigating simple model systems that are experimentally well-defined and can be unambiguously characterized and controlled. Such model systems help to elucidate the general principles that govern the structure and function of biointerfaces. These general principles, in turn, provide rational design rules for biointerfaces.
In case of DNA, homo-oligonucleotides—chemically uniform single-stranded DNA molecules—are a natural choice of model systems, in part because their chemical uniformity simplifies the preparation and characterization of model biointerfaces. The structure of such DNA monolayers before, during, and after hybridization experiments can be characterized using complementary ex situ and in situ techniques: x-ray photoelectron (XPS), Fourier transform infrared (FTIR), and near-edge x-ray absorption fine structure (NEXAFS) spectroscopies and surface plasmon resonance (SPR) imaging.
Understanding of DNA interactions with gold surfaces led to the discovery of a new immobilization method that is based on the intrinsic affinity of adenine nucleotides for gold. The method produces unique DNA brushes, for which grafting density and conformation can be independently and deterministically controlled. Quantitative analysis of such DNA brushes indicates that they provide reproducible and reversible hybridiza-tion and offer practical advantages of low cost and resistance to nonspecific adsorption of biomolecules.
Host: Adrian Mann