title: Micro- and nanofabrication of robust reactive arrays based on the covalent coupling of dendrimers to activated monolayers.
abstract: We report on methods to fabricate robust micro- and nanopatterned platforms, comprising high functional group densities and quasi three-dimensional structures, for possible applications in biochip array technologies. For this purpose, amine-terminated poly(amidoamine) (PAMAM) dendrimers were immobilized via amide linkage formation on 11,11'-dithiobis(N-hydroxysuccinimidylundecanoate) (NHS-C10) self-assembled monolayers (SAMs) on gold surfaces. The coupling reaction and the resulting assemblies were characterized by grazing incidence reflection Fourier transform infrared spectroscopy, contact angle measurements, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy; the obtained surface coverage values were successfully fitted with a Langmuir isotherm. The fraction of unreacted peripheral primary amine groups of the surface-immobilized PAMAM dendrimers was 28% as determined by XPS analysis of trifluoroacetic anhydride-labeled assemblies. Patterning of the PAMAM dendrimers on NHS-C10 SAMs on the micrometer and sub-100-nm scale was achieved by microcontact printing and dip pen nanolithography. The resulting patterns are characterized by their high degree of order and stability of the transferred molecules due to covalent attachment.
authors.affiliation: Materials Science and Technology of Polymers, MESA Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands.
authors.forename: Geerten H
authors.initials: GH
authors.lastname: Degenhart
authors.forename: Barbara
authors.initials: B
authors.lastname: Dordi
authors.forename: Holger
authors.initials: H
authors.lastname: Schönherr
authors.forename: G Julius
authors.initials: GJ
authors.lastname: Vancso
mesh_terms: D000327:Adsorption; D050091:Dendrimers; D005227:Fatty Acids / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011073:Polyamines / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013386:Succinates / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: C507589:11,11'-dithiobis(N-hydroxysuccinimidylundecanoate); D050091:Dendrimers; D005227:Fatty Acids; C104700:PAMAM Starburst; D011073:Polyamines; D013386:Succinates; D006046:Gold