Alignment of Gold Nanoparticle-Decorated DNA Origami
Nanotubes: Substrate Prepatterning versus Molecular Combing
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Abstract
DNA
origami has become an established technique for designing well-defined
nanostructures with any desired shape and for the controlled arrangement
of functional nanostructures with few nanometer resolution. These
unique features make DNA origami nanostructures promising candidates
for use as scaffolds in nanoelectronics and nanophotonics device fabrication.
Consequently, a number of studies have shown the precise organization
of metallic nanoparticles on various DNA origami shapes. In this work,
we fabricated large arrays of aligned DNA origami decorated with a
high density of gold nanoparticles (AuNPs). To this end, we first
demonstrate the high-yield assembly of high-density AuNP arrangements
on DNA origami adsorbed to Si surfaces with few unbound background
nanoparticles by carefully controlling the concentrations of MgCl<sub>2</sub> and AuNPs in the hybridization buffer and the hybridization
time. Then, we evaluate two methods, i.e., hybridization to prealigned
DNA origami and molecular combing in a receding meniscus, with respect
to their potential to yield large arrays of aligned AuNP-decorated
DNA origami nanotubes. Because of the comparatively low MgCl<sub>2</sub> concentration required for the efficient immobilization of the AuNPs,
the prealigned DNA origami become mobile and displaced from their
original positions, thereby decreasing the alignment yield. This increased
mobility, on the other hand, makes the adsorbed origami susceptible
to molecular combing, and a total alignment yield of 86% is obtained
in this way