jp9b11377_si_001.pdf (838.64 kB)
New Means to Control Molecular Assembly
Version 2 2020-03-09, 13:34
Version 1 2020-03-05, 20:43
journal contribution
posted on 2020-03-09, 13:34 authored by Jiali Zhang, Hai Yu, Bradley Harris, Yunbo Zheng, Umit Celik, Lan Na, Roland Faller, Xi Chen, Dominik R. Haudenschild, Gang-yu LiuWhile
self-assembly of molecules is relatively well-known and frequently
utilized in chemical synthesis and materials science, controlled assembly
of molecules represents a new concept and approach. The present work
demonstrates the concept of controlled molecular assembly using a
nonspherical biomolecule, heparosan tetrasaccharide (MW = 1.099 kD).
The key to controlled assembly is the fact that ultrasmall solution
droplets exhibit different evaporation dynamics from those of larger
ones. Using an independently controlled microfluidic probe in an atomic
force microscope, sub-femtoliter aqueous droplets containing designed
molecules produce well-defined features with dimensions as small as
tens of nanometers. The initial shape of the droplet and the concentration
of solute within the droplet dictate the final assembly of molecules
because of the ultrafast evaporation rate and dynamic spatial confinement
of the droplets. The level of control demonstrated in this work brings
us closer to programmable synthesis for chemistry and materials science
which can be used to develop vehicles for drug delivery and three-dimensional
nanoprinting in additive manufacturing.