Abstract
Nanoparticles functionalized with DNA can assemble into ordered superlattices with defined crystal habits through programmable DNA "bonds". Here, we examine the interactions of multivalent cations with these DNA bonds as a chemical approach for actuating colloidal superlattices. Multivalent cations alter DNA structure on the molecular scale, enabling the DNA "bond length" to be reversibly altered between 17 and 3 nm, ultimately leading to changes in the overall dimensions of the micrometer-sized superlattice. The identity, charge, and concentration of the cations each control the extent of actuation, with Ni2+ capable of inducing a remarkable >65% reversible change in crystal volume. In addition, these cations can increase "bond strength", as evidenced by superlattice thermal stability enhancements of >60 °C relative to systems without multivalent cations. Molecular dynamics simulations provide insight into the conformational changes in DNA structure as the bond length approaches 3 nm and show that cations that screen the negative charge on the DNA backbone more effectively cause greater crystal contraction. Taken together, the use of multivalent cations represents a powerful strategy to alter superlattice structure and stability, which can impact diverse applications through dynamic control of material properties, including the optical, magnetic, and mechanical properties.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 19973-19977 |
| Number of pages | 5 |
| Journal | Journal of the American Chemical Society |
| Volume | 141 |
| Issue number | 51 |
| DOIs | |
| State | Published - Dec 26 2019 |
Funding
This material is based upon work supported by the Air Force Office of Scientific Research award FA9550-17-1-0348 (PAE synthesis and assembly); the Vannevar Bush Faculty Fellowship program sponsored by the Basic Research Office of the Assistant Secretary of Defense for Research and Engineering and funded by the Office of Naval Research through grant N00014-15-1-0043 (oligonucleotide analyses); the Center for Bio-Inspired Energy Science, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under award DE-SC0000989 (PAE actuation and computational studies); and the National Cancer Institute of the National Institutes of Health under award U54CA199091 (imaging and microscopy). This material was also sponsored by the Air Force Research Laboratory under agreement FA8650-15-2-5518 (imaging and microscopy). This work made use of the EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205). SAXS experiments were performed at the Dupont–Northwestern–Dow Collaborative Access Team beamline at the Advanced Photon Source (APS) in Argonne National Laboratory, which receives support from the U.S. Department of Energy (DE-AC02-06CH11357). C.R.L. was supported through a Graduate Research Fellowship from the National Science Foundation. S.B.E. was supported in part by the Chicago Cancer Baseball Charities and the H Foundation at the Lurie Cancer Center of Northwestern University. K.E.B. was supported by a Banting Postdoctoral Fellowship from the Government of Canada. We are grateful to Dr. H. Lin for helpful discussions and Z. Urbach for assistance in collecting selected SAXS data.
ASJC Scopus subject areas
- General Chemistry
- Biochemistry
- Catalysis
- Colloid and Surface Chemistry