title: Core-shell silver nanoparticles for optical labeling of cells.
abstract: Silver nanoparticles have been modified with self-assembled monolayers of hydroxyl-terminated long chain thiols and encapsulated with a silica shell. The resulting core-shell nanoparticles were used as optical labels for cell analysis using flow cytometry and microscopy. The excitation of plasmon resonances in nanoparticles results in strong depolarized scattering of visible light, permitting detection at the single nanoparticle level. The nanoparticles were modified with neutravidin via epoxide-azide coupling chemistry, to which biotinylated antibodies targeting cell surface receptors were bound. The nanoparticle labels exhibited long-term stability in solutions with high salt concentrations without aggregation or silver etching. Labeled cells exhibited two orders of magnitude enhancement of the scattering intensity compared with unlabeled cells.
authors.affiliation: Department of Chemistry, Clemson University, Clemson, SC 29634, USA.
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Dukes
authors.affiliation: Department of Chemistry, Clemson University, Clemson, SC 29634, USA.
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Christensen
authors.affiliation: Department of Chemistry, Clemson University, Clemson, SC 29634, USA. Electronic address: gchumak@clemson.edu.
authors.forename: George
authors.initials: G
authors.lastname: Chumanov
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D055910:Antibodies, Immobilized / Q000276:immunology; D001360:Avidin / Q000737:chemistry; D002460:Cell Line; D005434:Flow Cytometry; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D008027:Light; D008264:Macrophages / Q000737:chemistry / Q000166:cytology; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D011956:Receptors, Cell Surface / Q000276:immunology; D012542:Scattering, Radiation; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D000906:Antibodies; D055910:Antibodies, Immobilized; D055767:Immobilized Proteins; D011956:Receptors, Cell Surface; C093483:neutravidin; D001360:Avidin; D012834:Silver
keywords: Flow cytometry; Light scattering; Plasmon resonance; Silver nanoparticles