AVS 49th International Symposium
    Biomaterials Thursday Sessions
       Session BI+HS+SS-ThM

Paper BI+HS+SS-ThM9
Covalent Attachment and Hybridization of DNA Oligomers at Polycrystalline Diamond Thin Films

Thursday, November 7, 2002, 11:00 am, Room C-201

Session: Biosensors and Biodiagnostics
Presenter: R.J. Hamers, University of Wisconsin-Madison
Authors: T. Knickerbocker, University of Wisconsin-Madison
W. Yang, University of Wisconsin-Madison
W. Cai, University of Wisconsin-Madison
J.N. Russell, Jr., Naval Research Laboratory
J. Butler, Naval Research Laboratory
D.M. Gruen, Argonne National Laboratory
J.A. Carlisle, Argonne National Laboratory
L.M. Smith, University of Wisconsin-Madison
D. Van der Weide, University of Wisconsin-Madison
R.J. Hamers, University of Wisconsin-Madison
Correspondent: Click to Email
Diamond has a number of unique properties, including a very wide range of electrochemical stability and very good electrical and thermal properties. These properties may make diamond a particularly attractive material to use as a substrate for biological sensors. We have explored the covalent bonding of DNA to several different types of diamond thin films, including free-standing polycrystalline films, thin films of microcrystalline diamond on silicon substrates, and ultrananocrystalline diamond thin films. Starting with H-terminated diamond, we prepared a homogeneous amine-terminated surface using a photochemical attachment processes, optimized using core-level photoemission spectroscopy. These amine-terminated diamond surfaces are then used as a starting point for subsequent attachment of DNA oligomers. The efficiency and selectivity of hybridization have been determined using conventional fluorescence measurements after the surface-bound oligomers are hybridized with fluorescently-tagged complementary and non-complementary oligomers. Our studies show that DNA-modified diamond surfaces show good hybridization properties and good selectivity. More importantly, the DNA-modified diamond surfaces show extremely good stability with repeated hybridizations, and retain this selectivity even after being dried and later reconstituted. This talk will discuss the fabrication of DNA-modified diamond surfaces for biosensor applications, and the differences and similarities between the various forms of DNA-modified diamond thin films.