title: Formation, characterization, and chemistry of undecanoic acid-terminated silicon surfaces: patterning and immobilization of DNA.
abstract: This paper describes a simple strategy for DNA immobilization on chemically modified and patterned silicon surfaces. The photochemical modification of hydrogen-terminated Si(111) with undecylenic acid leads to the formation of an organic monolayer covalently attached to the surface through Si-C bonds without detectable reaction of the carboxylic acid group, providing indirect support of a free radical mechanism. Chemical activation of the acid function was achieved by a simple chemical route using N-hydroxysuccinimide (NHS) in the presence of N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide hydrochloride. Single strand DNA with a 5'-dodecylamine group was then coupled to the NHS-activated surface by amide bond formation. Using a previously reported chemical patterning approach, we have shown that DNA can be immobilized on silicon surfaces in spatially well-resolved domains. Methoxytetraethyleneglycolamine was used to inhibit nonspecific adsorption. The resulting DNA-modified surfaces have shown good specificity and chemical and thermal stability under hybridization conditions. The sequential reactions on the surface were monitored by ATR-FTIR, X-ray Photoelectron Spectroscopy, and fluorescence spectroscopy.
authors.affiliation: Steacie Institute for Molecular Sciences, National Research Council, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 Canada.
authors.forename: Raluca
authors.initials: R
authors.lastname: Voicu
authors.forename: Rabah
authors.initials: R
authors.lastname: Boukherroub
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Bartzoka
authors.forename: Tim
authors.initials: T
authors.lastname: Ward
authors.forename: James T C
authors.initials: JT
authors.lastname: Wojtyk
authors.forename: Danial D M
authors.initials: DD
authors.lastname: Wayner
mesh_terms: D004247:DNA / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry*; D018613:Microscopy, Confocal; D015394:Molecular Structure; D010777:Photochemistry; D012825:Silicon / Q000737:chemistry*; D013053:Spectrophotometry
chemical_list: D005227:Fatty Acids; C016173:undecanoic acid; D004247:DNA; D012825:Silicon