This research was funded by Oregon Nanoscience and Microtechnologies Institute (ONAMI) and ONR under Contract No. N00014-08-1-1237 and NIH (2R15GM066279, R01GM080295 and R01GM080295S1, P41EB002027).
Journal of Vacuum Science and Technology A
Surface chemistry, Nanoparticles, Surface plasmon resonance, Immoblized ligands (Biochemistry), Activation (Chemistry)
Perfluorophenylazide (PFPA) chemistry is a novel method for tailoring the surface properties of solid surfaces and nanoparticles. It is general and versatile, and has proven to be an efficient way to immobilize graphene, proteins, carbohydrates, and synthetic polymers. The main thrust of this work is to provide a detailed investigation on the chemical composition and surface density of the PFPA tailored surface. Specifically, gold surfaces were treated with PFPA-derivatized (11-mercaptoundecyl) tetra(ethylene glycol) (PFPA-MUTEG) mixed with 2-[2-(2-mercaptoethoxy)ethoxy]ethanol (MDEG) at varying solution mole ratios. Complementary analytical techniques were employed to characterize the resulting films including Fourier transform infrared spectroscopy to detect fingerprints of the PFPA group, x-ray photoelectron spectroscopy and ellipsometry to study the homogeneity and uniformity of the films, and near edge x-ray absorption fine structures to study the electronic and chemical structure of the PFPA groups. Results from these studies show that the films prepared from 90:10 and 80:20 PFPA-MUTEG/MDEG mixed solutions exhibited the highest surface density of PFPA and the most homogeneous coverage on the surface. A functional assay using surface plasmon resonance with carbohydrates covalently immobilized onto the PFPAmodified surfaces showed the highest binding affinity for lectin on the PFPA-MUTEG/MDEG film prepared from a 90:10 solution.
Zorn, G., Castner, D. G., Tyagi, A., Wang, X., Wang, H., & Yan, M. (2015). Analysis of the surface density and reactivity of perfluorophenylazide and the impact on ligand immobilization. Journal of Vacuum Science & Technology A,33(2), 021407. and may be found at http://dx.doi.org/10.1116/1.4907924