Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

Abstract

SummaryThis study investigates the controlled chemical functionalization of silicon oxide nanostructures prepared by AFM-anodization lithography of alkyl-terminated silicon. Different conditions for the growth of covalently bound mono-, multi- or submonolayers of distinctively functional silane molecules on nanostructures have been identified by AFM-height investigations. Routes for the preparation of methyl- or amino-terminated structures or silicon surfaces are presented and discussed. The formation of silane monolayers on nanoscopic silicon oxide nanostructures was found to be much more sensitive towards ambient humidity than, e.g., the silanization of larger OH-terminated silica surfaces. Amino-functionalized nanostructures have been successfully modified by the covalent binding of functional fluorescein dye molecules. Upon excitation, the dye-functionalized structures show only weak fluorescence, which may be an indication of a relatively low surface coverage of the dye molecules on length scale that is not accessible by standard AFM measurements.

Functional superhydrophobic surfaces made of Janus micropillars

“…FITC was directly bound to the amine groups. 34 The GALA repeat was attached using a strategy based on azide–alkyne click chemistry. The amine groups were first coupled to the active ester dibenzylcyclooctyne- N -hydroxysuccinimide (DBCO-NHS ester).…”

“…The substrate was functionalised with FITC by immersion into a solution of FITC (39 mg) in acetone (10 mL) for 1.5 h, followed by thorough rinsing with fresh acetone, dichloromethane, and ethanol. 34 The silica tops were functionalised with the fluorescently labelled GALA peptide by being dipped overnight into a solution of dibenzylcyclooctyne- N -hydroxysuccinimide ester (DBCO-NHS ester, 0.1 mg L –1 ) in dimethylsulphoxide (DMSO, 5 mL), followed by washing with fresh DMSO and Milli-Q water (SI Methods). The DBCO-modified substrate was then immersed overnight in a solution of azide-functionalised GALA (0.1 mg L –1 ) in DMSO (5 mL), followed by thorough rinsing with fresh DMSO and Milli-Q water.…”

Nucleation and Assembly of Silica into Protein-Based Nanocomposites as Effective Anticancer Drug Carriers Using Self-Assembled Silk Protein Nanostructures as Biotemplates

“…29–31 We chose HeLa cells as model cancer cells to study the cellular uptake of silica composites. The cells were cultured in DMEM and supplemented with 10% FBS and 1% penicillin-streptomycin.…”

Raman Enhancement and Photo-Bleaching of Organic Dyes in the Presence of Chemical Vapor Deposition-Grown Graphene

“…Binding of APTES was carried out by immersion of the silicon substrate into a 10 mM solution of the APTES in toluene (spectroscopic grade) [ 19 ]. After 20 min, the sample was removed from the solution and rinsed in ultrasonic baths of toluene, dichloromethane, and ethanol for 10 min, respectively.…”