Observation of Protein Adsorption Using a Synthetic Nanopore

Abstract

Using the coulter counter technique with a single nanopore, we probed the non-specific adsorption of bovine serum albumin (BSA) to a silicon-based surface at the single molecule level. A potential bias was applied across a silicon nitride membrane containing a single nanopore that was immersed in KCl solution. Ionic current fluctuations across the nanopore revealed long-lived interactions of BSA with the silicon nitride. The nature of these interactions can be classified into two categories, suggesting that BSA adheres to the nitride surface in two distinct orientations. Knowing how proteins from the blood, like BSA, interact with silicon based materials is of growing importance as these materials are integrated into biosensors and medical devices. Acknowledgements: This research was supported by the NSF grant (DMR-0706517 and HRD-0703452) and the National Institutes of Health (R01 GM088403).