Published online 16 August 2004
Nucleic Acids Research, Vol. 32 No. 14 © Oxford University Press 2004; all rights reserved
Submicron patterning of DNA oligonucleotides on silicon
1 Microelectronics Research Centre, School of Electronics and Computer Science, 2 School of Chemistry and 3 Optoelectronics Research Centre, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
* To whom correspondence should be addressed at School of Electronics and Computer Science, University of Southampton, Highfield, Southampton, SO17 1BJ, UK. Tel: +44 0 23 8059 6505; Fax: +44 0 23 8059 3092; Email: tm{at}ecs.soton.ac.uk
Received June 9, 2004; Revised July 9, 2004; Accepted July 27, 2004
The covalent attachment of DNA oligonucleotides onto crystalline silicon (100) surfaces, in patterns with submicron features, in a straightforward, two-step process is presented. UV light exposure of a hydrogen-terminated silicon (100) surface coated with alkenes functionalized with N-hydroxysuccinimide ester groups resulted in the covalent attachment of the alkene as a monolayer on the surface. Submicron-scale patterning of surfaces was achieved by illumination with an interference pattern obtained by the transmission of 248 nm excimer laser light through a phase mask. The N-hydroxysuccinimide ester surface acted as a template for the subsequent covalent attachment of aminohexyl-modified DNA oligonucleotides. Oligonucleotide patterns, with feature sizes of 500 nm, were reliably produced over large areas. The patterned surfaces were characterized with atomic force microscopy, scanning electron microscopy, epifluorescence microscopy and ellipsometry. Complementary oligonucleotides were hybridized to the surface-attached oligonucleotides with a density of 7 x 1012 DNA oligonucleotides per square centimetre. The method will offer much potential for the creation of nano- and micro-scale DNA biosensor devices in silicon.