title: Functionalisation and immobilisation of an Au(110) surface via uracil and 2-thiouracil anchored layer.
abstract: We study surface functionalisation by uracil and 2-thiouracil, and immobilisation of several DNA moieties on functionalised gold surfaces. The combination of X-ray photoelectron and near-edge X-ray absorption spectroscopy allowed us to obtain a complete understanding of complex interfacial processes, starting from adsorption of biomolecules onto the metallic surface and progressing towards a specific surface functionality for interactions with other biologically related adsorbates. Au(110) surfaces were functionalised by deposition of uracil and 2-thiouracil molecules under vacuum conditions, and then tested for their selectivity by immobilisation of different DNA moieties deposited from aqueous solutions. We observed that adenine, adenosine, and RNA polymer (polyadenylic acid) from saturated solutions were immobilized successfully on the 2-thiouracil, but those from dilute (1%) solutions were not. However, cytosine failed to adsorb even from saturated solution. The chemical states of the biologically related adsorbates were investigated and the geometrical orientation of uracil and 2-thiouracil on the Au(110) surface was determined using both spectroscopic techniques.
authors.affiliation: Sincrotrone Trieste S.C.p.A., in Area Science Park, Strada Statale 14, km 163.5, I-34149 Basovizza, Trieste, Italy. oksana.plekan@elettra.trieste.it.
authors.forename: Oksana
authors.initials: O
authors.lastname: Plekan
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Feyer
authors.forename: Andrew
authors.initials: A
authors.lastname: Cassidy
authors.forename: Victor
authors.initials: V
authors.lastname: Lyamayev
authors.forename: Nataliya
authors.initials: N
authors.lastname: Tsud
authors.forename: Sylwia
authors.initials: S
authors.lastname: Ptasińska
authors.forename: Sara
authors.initials: S
authors.lastname: Reiff
authors.forename: Rober G
authors.initials: RG
authors.lastname: Acres
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Prince
mesh_terms: D000327:Adsorption; D006046:Gold / Q000737:chemistry*; D061925:Immobilized Nucleic Acids / Q000737:chemistry; D013499:Surface Properties; D013816:Thermodynamics; D013889:Thiouracil / Q000737:chemistry*; D014498:Uracil / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D061925:Immobilized Nucleic Acids; D014498:Uracil; D013889:Thiouracil; D006046:Gold