| AVS 56th International Symposium & Exhibition | |
| Biomaterial Interfaces | Friday Sessions |
| Session BI+AS+NS-FrM |
| Session: | Micro and Nanoengineering of Biointerfaces II |
| Presenter: | G.R. Marchesini, Joint Research Centre, European Commission, Italy |
| Authors: | G.R. Marchesini, Joint Research Centre, European Commission, Italy P. Lisboa, Joint Research Centre, European Commission, Italy A. Valsesia, Joint Research Centre, European Commission, Italy C. Pascual, Joint Research Centre, European Commission, Italy P. Colpo, Joint Research Centre, European Commission, Italy F. Rossi, Joint Research Centre, European Commission, Italy |
| Correspondent: | Click to Email |
Monitoring biomolecular recognition events with Surface Plasmon Resonance (SPR) heavily relies on the right surface chemistry. Uniform self assembled monolayers with carboxylic functional groups are widely used but might show steric hindrance, thus limiting the interpretation of the biorecognition kinetics. Furthermore, such negatively charged surface needs to be passivated upon immobilization of the ligand to prevent nonspecific electrostatic-driven binding of components from the analyte matrix.
In the present study we evaluate alternatives based on a 2D and 3D array of carboxylic nanodomains on a chemically contrasting matrix. By means of plasma-based colloidal lithography and e-beam lithography we were able to array ≈ 200 nm wide carboxylic motifs having a hexagonal 2-D crystalline structure on a gold surface. The interstitial gold was further modified with contrasting thiol chemistries or vapour enhanced deposition of nonadhesive material like poly ethylene oxide (PEO). The two 2D nanoarrayed chemical contrasts evaluated were carboxylic nanodomains on either a methyl-based or PEO-based matrix.
In addition, the 3D nanoarray based on a carboxylated dextran hydrogel matrix was evaluated for effects on the mass transport. In these cases, mass transport is one of the major challenges when measuring binding kinetics of biointeractants on a surface using a surface plasmon resonance (SPR) biosensor. The presence of a hydrogel on the surface increases the interactant density improving the sensitivity. Nevertheless, this is done at the expense of aggravating the mass transport phenomena.
The influence of the nanoarrayed chemical contrasts combined with the sensitivity improvement due to the band-gap effect on the kinetics of model biomolecular interactants was evaluated using an imaging SPR system and correlated with surface characterization techniques as atomic force microscopy, ellipsometry, and contact angle measurements.