A streptavidin linker layer that functions after drying.
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.
Xia
Nan
N
National ESCA and Surface Analysis Center for Biomedical Problems, Department of Chemical Engineering, University of Washington, Box 351750, Seattle, Washington 98195-1750, USA.
Shumaker-Parry
Jennifer S
JS
Zareie
M Hadi
MH
Campbell
Charles T
CT
Castner
David G
DG
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
D014867:Water; D001710:Biotin; D006046:Gold; D019809:Streptavidin