Chemoselective fabrication of high density peptide microarray by hetero-bifunctional tetra(ethylene glycol) linker for click chemistry conjugation.

A hetero-bifunctional tetra(ethylene glycol) molecule with silane and azide termini was synthesized, and this molecule was used to prepare azide-derivatized glass surface in one step. The resulting glass surface was available for fabricating peptide microarray by the conjugation with alkyne-containing peptide using click chemistry, which proceeded to the completion at low temperature and in aqueous solution. A high density of peptide on the surface was achieved due to concise overall procedure and highly efficient conjugation reaction. Immobilized peptides were highly bio-functional on the surface, as demonstrated by the ability to detect protease activity. Due to the biologically orthogonal manner of conjugation, peptide conjugated by site-specific immobilization was more accessible by protease than that conjugated by random amide conjugation. This site-specific and high efficient immobilization technique could be expanded to large scale development of biocompatible peptide and protein arrays for use in various applications.