Wednesday, 27 April 11:00am – 12:00pm

This seminar will be delivered in Online Zoom Please email chemistry.researchsupport@sydney.edu.au for zoom link and password.

Speaker: Dr Felix Rizzuto; University of New South Wales (UNSW)

Host: A/Prof. Markus Muellner

Title: Reprogramming DNA to build supramolecular polymers

Abstract: The programmability of DNA and its compatibility with oscillatory biological systems makes it an ideal material for generating out-of-equilibrium systems. However, the interactions and functionality of DNA are limited to the binary recognition of four nucleic acids, limiting the diversity of chemistries that can be performed with DNA and its ability to form new structural motifs for nanotechnology applications. Here, we will present two methods to reprogram the self-assembly pathways of single-stranded DNA: poly(adenine) recognises cyanuric acid to generate a hexamer that polymerises into micron-length fibres, while adding hydrophobic units to DNA forms a spherical micelle that melts to anneal a supramolecular polymer. As new tools for DNA nanotechnology, our constructs are orthogonal to native DNA base-pairing, can be built into two- and three-dimensional structures, and are highly dynamic. When coupled with a system of proton release and dissipation, we can directly observe a switch in the kinetic trajectory of self-assembly at the single-molecule level. This dissipative pathway heals gaps within our nanostructures, converting highly branched, interwoven networks into nanocable superstructures. Distinct from thermal annealing, our new method provides an alternate chemical route for ‘error-checking’ that improves the morphologies and properties of DNA nanomaterials using out-of-equilibrium systems.

Figure 1 Small molecules can reprogram the morphologies of DNA nanostructures.

References:

1. C. M. Platnich, F. J. Rizzuto, H. F. Sleiman, et al., Chem. Soc. Rev., 2020, 49, 4220-4233.
2. F. J. Rizzuto, H. F. Sleiman, et al., Nat. Chem., 2021, 13, 843-849.
3. F. J. Rizzuto, H. F. Sleiman, et al., Chem, 2020, 6, 1560-1575.
4. F. J. Rizzuto, H. F. Sleiman, C. Mao, H. Mao, et al., Nat. Mater., 2020, 19, 1012-1018.

Biography: Felix is a Group Leader and DECRA Fellow at UNSW. interfacing DNA nanotechnology with small molecule self-assembly and polymer chemistry to generate out-of-equilibrium supramolecular systems. He completed his PhD at the University of Cambridge with Prof Jonathan Nitschke in 2018 and was then a Banting Research Fellow with Prof Sleiman at McGill University until 2021.