1 research outputs found
DNA Origami Directed Au Nanostar Dimers for Single-Molecule Surface-Enhanced Raman Scattering
We demonstrate the synthesis of Au
nanostar dimers with tunable
interparticle gap and controlled stoichiometry assembled on DNA origami.
Au nanostars with uniform and sharp tips were immobilized on rectangular
DNA origami dimerized structures to create nanoantennas containing
monomeric and dimeric Au nanostars. Single Texas red (TR) dye was
specifically attached in the junction of the dimerized origami to
act as a Raman reporter molecule. The SERS enhancement factors of
single TR dye molecules located in the conjunction region in dimer
structures having interparticle gaps of 7 and 13 nm are 2 × 10<sup>10</sup> and 8 × 10<sup>9</sup>, respectively, which are strong
enough for single analyte detection. The highly enhanced electromagnetic
field generated by the plasmon coupling between sharp tips and cores
of two Au nanostars in the wide conjunction region allows the accommodation
and specific detection of large biomolecules. Such DNA-directed assembled
nanoantennas with controlled interparticle separation distance and
stoichiometry, and well-defined geometry, can be used as excellent
substrates in single-molecule SERS spectroscopy and will have potential
applications as a reproducible platform in single-molecule sensing