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Download fileVisualization of Multimerization and Self-Assembly of DNA-Functionalized Gold Nanoparticles Using In-Liquid Transmission Electron Microscopy
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posted on 2015-11-19, 00:00 authored by Sercan Keskin, Stephanie Besztejan, Günther Kassier, Stephanie Manz, Robert Bücker, Svenja Riekeberg, Hoc Khiem Trieu, Andrea Rentmeister, R. J. Dwayne MillerBase-pairing
stability in DNA-gold nanoparticle (DNA-AuNP) multimers
along with their dynamics under different electron beam intensities
was investigated with in-liquid transmission electron microscopy (in-liquid
TEM). Multimer formation was triggered by hybridization of DNA oligonucleotides
to another DNA strand (Hyb-DNA) related to the concept of DNA origami.
We analyzed the degree of multimer formation for a number of samples
and a series of control samples to determine the specificity of the
multimerization during the TEM imaging. DNA-AuNPs with Hyb-DNA showed
an interactive motion and assembly into 1D structures once the electron
beam intensity exceeds a threshold value. This behavior was in contrast
with control studies with noncomplementary DNA linkers where statistically
significantly reduced multimerization was observed and for suspensions
of citrate-stabilized AuNPs without DNA, where we did not observe
any significant motion or aggregation. These findings indicate that
DNA base-pairing interactions are the driving force for multimerization
and suggest a high stability of the DNA base pairing even under electron
exposure.