Invasive Cleavage Reactions
on DNA-Modified Diamond
Surfaces
Manchun Lu
1
Tanya Knickerbocker
1
Wei Cai
1
Wensha Yang
1
Robert J. Hamers
1
Lloyd M. Smith
1,2
1
Department of Chemistry,
University of Wisconsin-
Madison,
1101 University Avenue,
Madison, WI 53706-1396
2
Third Wave Technologies,
502 South Rosa Road,
Madison, WI 53719-1256
Received 16 July 2003;
accepted 1 August 2003
Published online 17 February 2004 in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/bip.20007
Abstract: Recently developed DNA-modified diamond surfaces exhibit excellent chemical stability
to high-temperature incubations in biological buffers. The stability of these surfaces is substantially
greater than that of gold or silicon surfaces, using similar surface attachment chemistry. The DNA
molecules attached to the diamond surfaces are accessible to enzymes and can be modified in
surface enzymatic reactions. An important application of these surfaces is for surface invasive
cleavage reactions, in which target DNA strands added to the solution may result in specific
cleavage of surface-bound probe oligonucleotides, permitting analysis of single nucleotide poly-
morphisms (SNPs). Our previous work demonstrated the feasibility of performing such cleavage
reactions on planar gold surfaces using PCR-amplified human genomic DNA as target. The
sensitivity of detection in this earlier work was substantially limited by a lack of stability of the gold
surface employed. In the present work, detection sensitivity is improved by a factor of 100 (100
amole of DNA target compared with 10 fmole in the earlier work) by replacing the DNA-modified
gold surface with a more stable DNA-modified diamond surface. © 2004 Wiley Periodicals, Inc.
Biopolymers 73: 606 – 613, 2004
Keywords: stability; stable surfaces; DNA chips; diamond; SNPs; invasive cleavage reaction
Correspondence to: Lloyd M. Smith; email: smith@
chem.wisc.edu
Contract grant sponsor: NIH
Contract grant number: R01HG02298
Biopolymers, Vol. 73, 606 – 613 (2004)
© 2004 Wiley Periodicals, Inc.
606