title: Understanding the role of thiol and disulfide self-assembled DNA receptor monolayers for biosensing applications.
abstract: A detailed study of the immobilization of three differently sulfur-modified DNA receptors for biosensing applications is presented. The three receptors are DNA-(CH)n-SH-, DNA-(CH)n-SS-(CH)n-DNA, and DNA-(CH)n-SS-DMTO. Nanomechanical and surface plasmon resonance biosensors and fluorescence and radiolabelling techniques were used for the experimental evaluation. The results highlight the critical role of sulfur linker type in DNA self-assembly, affecting the kinetic adsorption and spatial distribution of DNA chains within the monolayer and the extent of chemisorption and physisorption. A spacer (mercaptohexanol, MCH) is used to evaluate the relative efficiencies of chemisorption of the three receptors by analysing the extent to which MCH can remove physisorbed molecules from each type of monolayer. It is demonstrated that -SH derivatization is the most suitable for biosensing purposes as it results in densely packed monolayers with the lowest ratio of physisorbed probes.
authors.affiliation: Grupo de Nanobiosensores y Aplicaciones Bioanalíticas (nanoB2A), CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Bellaterra, Barcelona, Spain. lcarrascosa@cin2.es
authors.forename: Laura G
authors.initials: LG
authors.lastname: Carrascosa
authors.forename: Lidia
authors.initials: L
authors.lastname: Martínez
authors.forename: Yves
authors.initials: Y
authors.lastname: Huttel
authors.forename: Elisa
authors.initials: E
authors.lastname: Román
authors.forename: Laura M
authors.initials: LM
authors.lastname: Lechuga
mesh_terms: D000327:Adsorption; D001483:Base Sequence; D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry* / Q000378:metabolism; D005453:Fluorescence; D000441:Hexanols / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D056951:Photoelectron Spectroscopy; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry* / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: C033365:DNA receptor; D004220:Disulfides; D000441:Hexanols; D011956:Receptors, Cell Surface; D013438:Sulfhydryl Compounds; D004247:DNA; C477019:3-mercaptohexanol