AVS 53rd International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI-TuP

Paper BI-TuP2
Biosurfaces Generated Using AFM-Based Nanolithography and Surface Activation Chemistry

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Biomaterial Interfaces Poster Session
Presenter: J.N. Ngunjiri, Louisiana State University
Authors: J.N. Ngunjiri, Louisiana State University
W. Serem, Louisiana State University
J.C. Garno, Louisiana State University
Correspondent: Click to Email
The immobilization of biological ligands in precisely defined locations on surfaces is a critical technology for the integration of biological molecules into miniature bioelectronics and sensing devices. The selectivity of protein adsorption with designed surfaces is compared at the nanoscale using in situ atomic force microscopy (AFM). The high-resolution capability of AFM characterization is combined with nanografting for investigations of protein binding on chemically activated self-assembled monolayers (SAM). Using a computer program, the AFM tip is translated at designated speed, direction, and force to enable fabrication of arrays of SAM nanopatterns with well-defined shapes and sizes. Nanografting provides superb control of parameters of ligand density, pattern spacing and the size of array elements. Nanostructures ranging in size from 10-100 nm are inscribed within a resistive matrix SAM (such as methyl or hydroxyl) which imparts selectivity for protein adsorption. The terminal moieties of carboxylate-terminated SAMs can be reacted with coupling agents such as N-ethyl-N'(dimethylaminoporpyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to establish covalent coupling of proteins to arrays of SAM nanopatterns. The activity of the immobilized proteins for binding immunoglobulin G (IgG) and peptides can then be investigated by viewing successive changes in the height and morphology of nanostructures during in situ AFM experiments. The resistive matrix SAM surrounding the nanopatterned proteins selectively defines regions for viewing adsorption of proteins with exquisite detail. In situ AFM images of nanoengineered surfaces will be presented which provide direct views of the progression of biomolecular reactions on surfaces.