title: Size-Selective Nanoparticle Assembly on Substrates by DNA Density Patterning.
abstract: The vision of nanoscale self-assembly research is the programmable synthesis of macroscale structures with controlled long and short-range order that exhibit a desired set of properties and functionality. However, strategies to reliably isolate and manipulate the nanoscale building blocks based on their size, shape, or chemistry are still in their infancy. Among the promising candidates, DNA-mediated self-assembly has enabled the programmable assembly of nanoparticles into complex architectures. In particular, two-dimensional assembly on substrates has potential for the development of integrated functional devices and analytical systems. Here, we combine the high-resolution patterning capabilities afforded by electron-beam lithography with the DNA-mediated assembly process to enable direct-write grayscale DNA density patterning. This method allows modulation of the functionally active DNA surface density to control the thermodynamics of interactions between nanoparticles and the substrate. We demonstrate that size-selective directed assembly of nanoparticle films from solutions containing a bimodal distribution of particles can be realized by exploiting the cooperativity of DNA binding in this system. To support this result, we study the temperature-dependence of nanoparticle assembly, analyze the DNA damage by X-ray photoelectron spectroscopy and fluorescence microscopy, and employ molecular dynamics simulations to explore the size-selection behavior.
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|NUANCE Center, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Myers
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Lin
authors.affiliation: Department of Physics and Astronomy, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Huanxin
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|Department of Physics and Astronomy, Northwestern University , Evanston, Illinois 60208, United States.|Department of Engineering Sciences and Applied Mathematics, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Erik
authors.initials: E
authors.lastname: Luijten
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|International Institute for Nanotechnology, Northwestern University , Evanston, Illinois 60208, United States.|Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|NUANCE Center, Northwestern University , Evanston, Illinois 60208, United States.|International Institute for Nanotechnology, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Vinayak P
authors.initials: VP
authors.lastname: Dravid
mesh_terms: D004247:DNA / Q000737:chemistry*; D053758:Nanoparticles; D036103:Nanotechnology; D011327:Printing
chemical_list: D004247:DNA
keywords: DNA nanotechnology; directed assembly; electron-beam lithography; nanoparticle assembly; nanopatterning; self-assembly