Visualization of multimerization and self-assembly of DNA-functionalized gold nanoparticles using in-liquid transmission electron microscopy

J Phys Chem Lett. 2015 Nov 19;6(22):4487-92. doi: 10.1021/acs.jpclett.5b02075. Epub 2015 Oct 30.

Abstract

Base-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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Citrates / chemistry
  • DNA / chemistry*
  • Drug Stability
  • Gold / chemistry*
  • Metal Nanoparticles / chemistry*
  • Microscopy, Electron, Transmission*
  • Models, Molecular
  • Nucleic Acid Conformation
  • Surface Properties

Substances

  • Citrates
  • Gold
  • DNA