AMADEus Seminar - Dr. Etienne Ducrot - Monday 4 January 2016, 4:00 pm - ICMCB (Amphi)le 04/01 à 16h
Dr. Etienne Ducrot
Center for Soft Matter Research, Department of Physics, New York University, New York, New York 10003, USA
DNA as programmable glue for the self assembly of micron sized colloids
DNA coatings have been proposed as a versatile means for programming the self-assembly of micrometer and nanometer size particles. Progress in achieving this goal for particles larger than about 100 nm, where the thickness of the DNA brush is typically much smaller than the particle diameter, has been impeded because such DNA-coated colloids collide and bind but fail to anneal into their preprogrammed structure. Most notably, they fail to assemble into colloidal crystals but form random aggregates.
We recently developed synthetic strategies [1,2] to coat colloidal particles with DNA that can bind at low temperature and stay mobile while bound so that the particles can rapidly rearrange and crystallize. We measured the mobility of bound DNA coated particles when the system is quenched just below the melting temperature. For shallow quenches, the particles exhibit a diffusive motion. For deeper quenches, the motion becomes subdiffusive. This behavior is linked to quench dependent crystallization observations.
Appling various synthetic strategies, organic, inorganic and hybrid materials can be coated with DNA. Once annealed, those colloids lead to self organized complex structures where particles of different size and materials are combined, opening the way to functional materials.
 Y. Wang, Y. Wang, X. Zheng, E. Ducrot, J. S. Yodh, M. Weck, and D. J. Pine, Nat. Commun. 6, (2015).
 Y. Wang, Y. Wang, X. Zheng, E. Ducrot, M.-G. Lee, G.-R. Yi, M. Weck, and D. J. Pine, J. Am. Chem. Soc. 137, 10760 (2015).