title: Immobilization of proteins on carboxylic acid functionalized nanopatterns.
abstract: The immobilization of proteins on nanopatterned surfaces was investigated using in situ atomic force microscopy (AFM) and ex situ infrared reflectance-absorption spectroscopy (IRAS). The AFM-based lithography technique of nanografting provided control of the size, geometry, and spatial placement of nanopatterns within self-assembled monolayers (SAMs). Square nanopatterns of carboxylate-terminated SAMs were inscribed within methyl-terminated octadecanethiolate SAMs and activated using carbodiimide/succinimide coupling chemistry. Staphylococcal protein A was immobilized on the activated nanopatterns before exposure to rabbit immunoglobulin G. In situ AFM was used to monitor changes in the topography and friction of the nanopatterns in solution upon protein immobilization. Complementary studies with ex situ IRAS confirmed the surface chemistry that occurred during the steps of SAM activation and subsequent protein immobilization on unpatterned samples. Since carbodiimide/succinimide coupling chemistry can be used for surface attachment of different biomolecules, this protocol shows promise for development of other aqueous-based studies for nanopatterned protein immobilization.
authors.affiliation: Analytical Science Division, The Dow Chemical Company, 727 Norristown Rd., Spring House, PA 19477, USA. jngunjiri@Dow.com
authors.forename: Johnpeter N
authors.initials: JN
authors.lastname: Ngunjiri
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Stark
authors.forename: Tian
authors.initials: T
authors.lastname: Tian
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Briggman
authors.forename: Jayne C
authors.initials: JC
authors.lastname: Garno
mesh_terms: D000818:Animals; D002264:Carboxylic Acids / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D055767:Immobilized Proteins / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D011817:Rabbits; D013057:Spectrum Analysis; D013205:Staphylococcal Protein A / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000737:chemistry; D013499:Surface Properties
chemical_list: D002264:Carboxylic Acids; D003432:Cross-Linking Reagents; D055767:Immobilized Proteins; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A