Colloidal physics with DNA particles

DNA oligomers can nowadays be assembled to produce a large variety of nanometric constructs, via a cascade of self-assembly processes, each one guided by the length of complementary sequences of distinct DNA strands. In the talk I will show that it is possible to build bulk quantities of DNA-made nanoparticles that closely match idealized colloids, transferring modern in-paper and in-silico intuitions into experimental realizations[1-4]. I will show how unconventional collective behaviors, recently explored theoretically, can indeed be reproduced in the lab. Among others I will discuss how the selectivity of the DNA interactions can be exploited to create gels that form both on cooling and on heating [5-6], how to create networks with swappable bonds[7], how to create systems residing on the verge of a percolation transition.

[1] E. Bianchi, J. Largo, P. Tartaglia, E. Zaccarelli, F. Sciortino Phase diagram of patchy colloids: towards empty liquids, Phys. Rev. Lett. 97, 168301, (2006).
[2] F. Sciortino and E. Zaccarelli Reversible gels of patchy particles, Current Opinion in Solid State and Materials Science 15, 246-253 (2011).
[3] S. Biffi, R. Cerbino, F. Bomboi E. M. Paraboschi, R. Asselta, F. Sciortino and T. Bellini, Phase behavior and critical activated dynamics of limited-valence DNA nanostars, Proc. Nat. Acad. Science, 110 15633-15(2013)..
[4] S. Biffi, R. Cerbino, G. Nava, F. Bomboi, F. Sciortino and T. Bellini, Equilibrium gels of low-valence DNA nanostars: a colloidal model for strong glass formers, Soft Matter, 11, 3132 (2015).
[5] S. Roldán-Vargas, F. Smallenburg, W. Kob and F. Sciortino, Phase diagram of a reentrant gel of patchy particles, J. Chem. Phys. 139, 244910 (2013);
[6] F. Bomboi, F. Romano, M. Leo, J. Fernandez-Castanon, R. Cerbino, T. Bellini, F. Bordi, P. Filetici & F. Sciortino, Re-entrant DNA gels Nat. Commun. 7, 13191 (2016).
[7 F. Romano and F. Sciortino, Switching Bonds in a DNA Gel: An All-DNA Vitrimer, Phys. Rev. Letts. 114, 078104 (2015).