Single Molecules Studies of Two-Dimensional Catenated Polymers

The physics of 2D polymers diverge from those of traditional polymer chains. In solution, a 1D polymer chain adopts a random coil configuration, a disordered and isotropic structure, that maximizes entropy while satisfying the constraints of electrostatic interactions between monomers. In contrast, 2D polymers are predicted to maintain a sheet-like configuration and appear planar in solution with minimal out-of-plane crumpling. We use microfluidics in conjunction with fluorescence microscopy to study the physics of 2D catenated polymers using kinetoplast as a model system. A single kinetoplast is a 2D network of thousands of linked DNA rings akin to molecular chainmail. It offers an easy and versatile possibility to tune its molecular topology using enzymes, while maintaining planar conformation, and thus study the structure-property relation. Particularly we are interested in the solution behaviour of 2D polymers, e.g., what is the nature of conformational transition of a 2D polymer and how it responds to external fields and flow.
References:
A. R. Klotz, B. W. Soh, and P. S. Doyle, Equilibriumstructure and Deformation Response of 2D Kinetoplast Sheets, PNAS 117, 121 (2020).
B. W. Soh and P. S. Doyle, Deformation Response of Catenated DNA Networks in a Planar Elongational Field, ACS Macro Letters 9, 944 (2020).
B. W. Soh, A. Khorshid, D. Al Sulaiman, and P. S. Doyle, Ionic Effects on the Equilibrium Conformation of Catenated DNA Networks, Macromolecules 53, 8502 (2020).
B. W. Soh and P. S. Doyle, Equilibrium Conformation of Catenated DNA Networks in Slitlike Confinement, ACS Macro Letters , 880 (2021).
I. Yadav, D. Al Sulaiman, B. W. Soh, and P. S. Doyle, Phase Transition of Catenated DNA Networks in Poly(ethylene glycol) Solutions, ACS Macro Letters 10, 1429 (2021).
I. Yadav, D. Al Sulaiman, and P. S. Doyle, Tuning the Topology of a Two-Dimensional Catenated DNA Network, https://doi.org/10.48550/arXiv.2209.04486.