Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
602742 | Colloids and Surfaces B: Biointerfaces | 2007 | 6 Pages |
Abstract
Crystalline cell surface layer proteins (S-layers) can be used in electrochemical fabrication to create nanoscale arrays of metals and oxides on surfaces so long as the proteins maintain their long-range order during processing. We have explored the stability of the HPI layer protein (the S-layer protein from the microorganism Deinococcus radiodurans) adsorbed onto platinum surfaces after immersion in sulfuric acid or sodium hydroxide electrolytes ranging in pH from 0 to 14 over time periods ranging from 1 to 1000Â s. Topographic data obtained by atomic force microscopy (AFM) was used to characterize the protein stability, judged by its retention of long-range order after immersion. The compiled data revealed that, under these solution conditions and in this environment, the HPI layer protein has a dose-dependent structural stability “envelope” in the acidic range from 1Â <Â pHÂ <Â 4. The protein retains its long-range order up to 1000Â s from pH 4 to 11, and has a sharp stability edge between pH 12 and 13. Interestingly, the more stringent requirement of stability (i.e., retention of long-range order) defined in the context of electrochemical fabrication for this protein narrowed the window of stability in pH and time when compared to previous stability studies reported for this protein.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Alvaro Presenda, Daniel B. Allred, François Baneyx, Daniel T. Schwartz, Mehmet Sarikaya,