title: A streptavidin linker layer that functions after drying.
abstract: The ability of streptavidin (SA) to simultaneously bind four biotins is often used in linker layers, where a biotinylated molecule is linked to a biotin-functionalized surface via SA. For biosensor and array applications, it is desirable that the SA linker layer be stable to drying and rehydration. In this study it was observed that a significant decrease in binding capacity of a SA layer occurred when that layer was dried. For this study a SA linker layer was constructed by binding SA to a biotin-containing alkylthiolate monolayer (BAT/OEG) self-assembled onto gold. Its stability after drying was investigated using surface plasmon resonance (SPR). Approximately a quarter of the SA layer was removed from the BAT/OEG surface upon drying and rehydration, suggesting disruption of SA-biotin binding when dry. This resulted in the dried SA layer losing approximately 40% of its biotinylated ferritin (BF) binding capacity. Coating the layer with trehalose before drying was found to inhibit the loss of SA from the BAT/OEG surface. SPR showed that the trehalose-protected SA linker layer retained approximately 91% of its original BF binding capacity after drying and rehydration. Atomic force microscopy, which was used to image individual surface-bound SA and BF molecules, qualitatively confirmed these observations.
authors.affiliation: National ESCA and Surface Analysis Center for Biomedical Problems, Department of Chemical Engineering, University of Washington, Box 351750, Seattle, Washington 98195-1750, USA.
authors.forename: Nan
authors.initials: N
authors.lastname: Xia
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Shumaker-Parry
authors.forename: M Hadi
authors.initials: MH
authors.lastname: Zareie
authors.forename: Charles T
authors.initials: CT
authors.lastname: Campbell
authors.forename: David G
authors.initials: DG
authors.lastname: Castner
mesh_terms: D001710:Biotin / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D018625:Microscopy, Atomic Force; D019809:Streptavidin / Q000737:chemistry* / Q000648:ultrastructure; D020349:Surface Plasmon Resonance; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D001710:Biotin; D006046:Gold; D019809:Streptavidin