title: Self-assembled nanoparticle probes for recognition and detection of biomolecules.
abstract: Colloidal gold nanocrystals have been used to develop a new class of nanobiosensors that is able to recognize and detect specific DNA sequences and single-base mutations in a homogeneous format. At the core of this biosensor is a 2.5-nm gold nanoparticle that functions as both a nano-scaffold and a nano-quencher (efficient energy acceptor). Attached to this core are oligonucleotide molecules labeled with a thiol group at one end and a fluorophore at the other. This hybrid bio/inorganic construct is found to spontaneously assemble into a constrained arch-like conformation on the particle surface. Binding of target molecules results in a conformational change, which restores the fluorescence of the quenched fluorophore. Unlike conventional molecular beacons with a stem-and-loop structure, the nanoparticle probes do not require a stem, and their background fluorescence increases little with temperature. In comparison with the organic quencher Dabcyl (4,4'-dimethylaminophenyl azo benzoic acid), metal nanoparticles have unique structural and optical properties for new applications in biosensing and molecular engineering.
authors.affiliation: Contribution from the Department of Chemistry, Indiana University, Bloomington 47405, USA.
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Maxwell
authors.forename: Jason R
authors.initials: JR
authors.lastname: Taylor
authors.forename: Shuming
authors.initials: S
authors.lastname: Nie
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D007700:Kinetics; D015335:Molecular Probes; D009154:Mutation; D036103:Nanotechnology; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D015335:Molecular Probes; D004247:DNA