Abstract
Cu-free "click" chemistry is explored on silicon nitride (Si3N4) surfaces as an effective way for oriented immobilization of biomolecules. An omega-unsaturated ester was grafted onto Si3N4 using UV irradiation. Hydrolysis followed by carbodiimide-mediated activation yielded surface-bound active succinimidyl and pentafluorophenyl ester groups. These reactive surfaces were employed for the attachment of bicyclononyne with an amine spacer, which subsequently enabled room temperature strain-promoted azide alkyne cycloaddition (SPAAC). This stepwise approach was characterized by means of static water contact angle, X-ray photoelectron spectroscopy, and fluorescence microscopy. The surface-bound SPAAC reaction was studied with both a fluorine-tagged azide and an azide-linked lactose, yielding hydrophobic and bioactive surfaces for which the presence of trace amounts of Cu ions would have been problematic. Additionally, patterning of the Si3N4 surface using this metal-free click reaction with a fluorescent azide is shown. These results demonstrate the ability of the SPAAC as a generic tool for anchoring complex molecules onto a surface under extremely mild, namely ambient and metal-free, conditions in a clean and relatively fast manner.
Original language | English |
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Pages (from-to) | 8651-8663 |
Journal | Langmuir |
Volume | 28 |
Issue number | 23 |
DOIs | |
Publication status | Published - 2012 |
Keywords
- self-assembled monolayers
- terminated monolayers
- organic monolayers
- one-step
- functionalization
- chemistry
- films
- immobilization
- microarrays
- dna