title: Increased stability of mercapto alkane functionalized Au nanoparticles towards DNA sensing.
abstract: The use of gold nanoparticles (GNPs) in bioassays is often hampered by their colloidal stability. In this study, gold nanoparticles coated with different mercapto alkanes were investigated towards their stability. Hereto, the effects of the alkane chain length (5-11 methylene groups), the type of functional end-group (-OH or -COOH) and the amount of incorporated poly-ethylene oxide units (none, 3 or 6) on the GNP stabilization was evaluated. Based on these results, an optimal mercapto alkane (HS(CH(2))(11)PEO(6)COOH) was selected to increase the colloidal stability up to 2 M NaCl. Furthermore, it was proved that this mercapto alkane is ideally suited to enhance the stability of DNA functionalized GNPs in high electrolytic hybridization buffers. The effectiveness of these DNA functionalized GNPs was demonstrated in a sandwich assay using a surface plasmon resonance biosensor. The superior stability of these nanoparticles during hybridization may lead to enhanced biosensor technologies.
authors.affiliation: IMEC, Functional Nanosystems, Kapeldreef 75, B-3001 Leuven, Belgium. Hilde.Jans@imec.be
authors.forename: H
authors.initials: H
authors.lastname: Jans
authors.forename: T
authors.initials: T
authors.lastname: Stakenborg
authors.forename: K
authors.initials: K
authors.lastname: Jans
authors.forename: B
authors.initials: B
authors.lastname: Van de Broek
authors.forename: S
authors.initials: S
authors.lastname: Peeters
authors.forename: K
authors.initials: K
authors.lastname: Bonroy
authors.forename: L
authors.initials: L
authors.lastname: Lagae
authors.forename: G
authors.initials: G
authors.lastname: Borghs
authors.forename: G
authors.initials: G
authors.lastname: Maes
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D019343:Citric Acid / Q000737:chemistry; D004247:DNA / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization; D010316:Particle Size; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D000473:Alkanes; D013438:Sulfhydryl Compounds; D019343:Citric Acid; D006046:Gold; D004247:DNA