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) using custom developed silicon nitride based liquid cells. 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. These findings indicate that DNA base pairing interactions are the driving force for in situ multimerization and DNA-metallic NP conjugates provide excellent models to understand structure-function correlation in biological systems with nanometer spatial resolution (Keskin et al., 2015, 10.1021/acs.jpclett.5b02075).
Acknowledgements:
This work was funded by the Max Planck Society and supported by the cluster of excellence “The Hamburg Centre of Ultrafast Imaging” (CUI). We thank, in particular, Josef Gonschior for the design of the liquid specimen holder. Furthermore, we thank the Centre for Applied Nanotechnologies (CAN), Hamburg, Germany (in particular, Katja Werner and Christian Supej) for generously providing the gold nanoparticles and technical assistance in coupling.
Figures:
Figure 1: (A) Schematic illustration of the observed DNA-AuNP conjugates in the nanofluidic cell and (B) their hybridization, (C) in-liquid TEM image of a large multimer, (D) In-liquid TEM images of a small DNA-AuNP (18 nm) bridged to a large DNA-AuNP (55 nm) at different time points, (E) In-liquid TEM images showing the self-assembly of DNA-AuNPs.
To cite this abstract:
Sercan Keskin, Stephanie Besztejan, Guenther Kassier, Stephanie Manz, Robert Buecker, Svenja Riekeberg, Hoc Khiem Trieu, Andrea Rentmeister, Dwayne Miller; In-liquid TEM to visualize multimerization and self-assembly of DNA functionalized gold nanoparticles. The 16th European Microscopy Congress, Lyon, France. https://emc-proceedings.com/abstract/in-liquid-tem-to-visualize-multimerization-and-self-assembly-of-dna-functionalized-gold-nanoparticles/. Accessed: September 21, 2023« Back to The 16th European Microscopy Congress 2016
EMC Abstracts - https://emc-proceedings.com/abstract/in-liquid-tem-to-visualize-multimerization-and-self-assembly-of-dna-functionalized-gold-nanoparticles/