title: A photochemically initiated chemistry for coupling underivatized carbohydrates to gold nanoparticles.
abstract: The sensitive optoelectronic properties of metal nanoparticles make nanoparticle-based materials a powerful tool to study fundamental biorecognition processes. Here we present a new and versatile method for coupling underivatized carbohydrates to gold nanoparticles (Au NPs) via the photochemically induced reaction of perfluorophenylazide (PFPA). A one-pot procedure was developed where Au NPs were synthesized and functionalized with PFPA by a ligand-exchange reaction. Carbohydrates were subsequently immobilized on the NPs by a fast light activation. The coupling reaction was efficient, resulting in high coupling yield as well as high ligand surface coverage. A colorimetric system based on the carbohydrate-modified Au NPs was used for the sensitive detection of carbohydrate-protein interactions. Binding and cross-reactivity studies were carried out between carbohydrate-functionalized Au NPs and lectins. Results showed that the surface-bound carbohydrates not only retained their binding affinities towards the corresponding lectin, but also exhibited affinity ranking consistent with that of the free ligands in solution.
authors.affiliation: Department of Chemistry, Portland State University, P.O. Box 751, Portland, Oregon, 97207-075, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Olof
authors.initials: O
authors.lastname: Ramström
authors.forename: Mingdi
authors.initials: M
authors.lastname: Yan