title: Silica encapsulation of fluorescent nanodiamonds for colloidal stability and facile surface functionalization.
abstract: Fluorescent nanodiamonds (FNDs) emit in the near-IR and do not photobleach or photoblink. These properties make FNDs better suited for numerous imaging applications compared with commonly used fluorescence agents such as organic dyes and quantum dots. However, nanodiamonds do not form stable suspensions in aqueous buffer, are prone to aggregation, and are difficult to functionalize. Here we present a method for encapsulating nanodiamonds with silica using an innovative liposome-based encapsulation process that renders the particle surface biocompatible, stable, and readily functionalized through routine linking chemistries. Furthermore, the method selects for a desired particle size and produces a monodisperse agent. We attached biotin to the silica-coated FNDs and tracked the three-dimensional motion of a biotinylated FND tethered by a single DNA molecule with high spatial and temporal resolution.
authors.affiliation: Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Building 50, Room 3517, Bethesda, Maryland 20892, USA.
authors.forename: Ambika
authors.initials: A
authors.lastname: Bumb
authors.forename: Susanta K
authors.initials: SK
authors.lastname: Sarkar
authors.forename: Neil
authors.initials: N
authors.lastname: Billington
authors.forename: Martin W
authors.initials: MW
authors.lastname: Brechbiel
authors.forename: Keir C
authors.initials: KC
authors.lastname: Neuman
mesh_terms: D003102:Colloids / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D005453:Fluorescence; D008081:Liposomes; D058612:Nanodiamonds; D012822:Silicon Dioxide / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D013499:Surface Properties
chemical_list: D003102:Colloids; D008081:Liposomes; D058612:Nanodiamonds; D012822:Silicon Dioxide; D004247:DNA