Visible wavelength spectral tuning of absorption and circular dichroism of DNA-assembled Au/Ag core-shell nanorod assemblies

Plasmonic nanoparticles have unique properties which can be harnessed to manipulate light at the nanoscale. With recent advances in synthesis protocols that increase their stability, gold-silver core-shell nanoparticles have become suitable building blocks for plasmonic nanostructures to expand the range of attainable optical properties. Here we tune the plasmonic response of gold-silver core-shell nanorods over the visible spectrum by varying the thickness of the silver shell. Through the chiral arrangement of the nanorods with the help of various DNA origami designs, the spectral tunability of the plasmon resonance frequencies is transferred into circular dichroism signals covering the spectrum from 400 nm to 700 nm. Our approach could aid in the construction of better sensors as well as metamaterials with a tunable optical response in the visible region

A label-free light-scattering method to resolve assembly and disassembly of DNA nanostructures

Funding Information: We thank V. Aseyev, E. Riedle, and H. Derondeau for technical assistance and fruitful discussions. We thank A. Kucinic and C.E. Castro, who kindly provided us with staple mixtures and scaffolds for the four structures shown in Fig. 4. Financial support by the Emil Aaltonen Foundation, the Sigrid Jusélius Foundation, the Jane and Aatos Erkko Foundation, and ERC consolidator grant “DNA functional lattices” (project ID: 818635) is gratefully acknowledged. This work was carried out under the Academy of Finland Centers of Excellence Program (2022–2029) in Life-Inspired Hybrid Materials (LIBER), project number (346110). We acknowledge the provision of facilities and technical support by Aalto University Bioeconomy Facilities and OtaNano – Nanomicroscopy Center (Aalto-NMC) and Micronova Nanofabrication Center. The authors declare no competing interests. Publisher Copyright: © 2022 Biophysical SocietyDNA self-assembly, and in particular DNA origami, has evolved into a reliable workhorse for organizing organic and inorganic materials with nanometer precision and with exactly controlled stoichiometry. To ensure the intended performance of a given DNA structure, it is beneficial to determine its folding temperature, which in turn yields the best possible assembly of all DNA strands. Here, we show that temperature-controlled sample holders and standard fluorescence spectrometers or dynamic light-scattering setups in a static light-scattering configuration allow for monitoring the assembly progress in real time. With this robust label-free technique, we determine the folding and melting temperatures of a set of different DNA origami structures without the need for more tedious protocols. In addition, we use the method to follow digestion of DNA structures in the presence of DNase I and find strikingly different resistances toward enzymatic degradation depending on the structural design of the DNA object.Peer reviewe

Redefinición de las estructuras narrativas publicitarias

La flexibilidad de la imagen digital y el advenimiento de los nuevos medios interactivos off line y on line suponen un punto de inflexión en las estructuras de los relatos publicitarios, tanto lineales como interactivos. Internet, la red de redes, ya ha empezado su mutación multimedia y la televisión digital, su mutación interactiva. La Web TV presagia una nueva y fructífera convergencia. Estos nuevos escenarios hipermedia obligan a redefinir las estructuras publicitarias existentes y a crear otras radicalmente nuevas