scholarly journals Long- and Short-Ranged Chiral Interactions in DNA Assembled Plasmonic Chains

2020 ◽  
Author(s):  
Kevin Martens ◽  
Felix Binkowski ◽  
Linh Nguyen ◽  
Li Hu ◽  
Alexander Govorov ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Optical Materials ◽  
Dna Origami ◽  
Plasmonic Nanostructures ◽  
Biological Processes ◽  
Optical Fields ◽  
Metallic Structures ◽  
Complex Architectures ◽  
The Individual ◽  
Sample Homogeneity

Abstract Molecular chirality plays a crucial role in innumerable biological processes. The chirality of a molecule can typically be identified by its characteristic optical response, the circular dichroism (CD). CD signals have thus long been used to identify the state of molecules or to follow dynamic protein configurations. In recent years, the focus has moved towards plasmonic nanostructures, as they show potential for applications ranging from pathogen sensing to novel optical materials. The plasmonic coupling of the individual elements of such chiral metallic structures is a crucial prerequisite to obtain sizeable CD signals. We here identified and implemented various coupling entities - chiral and achiral - to obtain chiral transfer over distances close to 100 nm. The coupling is realized by an achiral nanosphere situated between a pair of gold nanorods that are arranged far apart but in a chiral fashion. We synthesized these structures with nanometer precision using DNA origami and obtained sample homogeneity that allowed us to directly demonstrate efficient chiral energy transfer between the distant nanorods. The transmitter particle causes a strong enhancement in amplitude of the CD response, the emergence of an additional chiral feature at the resonance frequency of the nanosphere, and a redshift of the longitudinal plasmonic resonance frequency of the nanorods. Numerical simulations closely match our experimental observations and give insights in the intricate behavior of chiral optical fields and the transfer of plasmons in complex architectures.

scholarly journals Long- and short-ranged chiral interactions in DNA-assembled plasmonic chains

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kevin Martens ◽  
Felix Binkowski ◽  
Linh Nguyen ◽  
Li Hu ◽  
Alexander O. Govorov ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Gold Nanorods ◽  
Optical Materials ◽  
Dna Origami ◽  
Plasmonic Nanostructures ◽  
Plasmonic Resonance ◽  
Optical Fields ◽  
Metallic Structures ◽  
Complex Architectures ◽  
The Individual

AbstractCircular dichroism (CD) has long been used to trace chiral molecular states and changes of protein configurations. In recent years, chiral plasmonic nanostructures have shown potential for applications ranging from pathogen sensing to novel optical materials. The plasmonic coupling of the individual elements of such metallic structures is a crucial prerequisite to obtain sizeable CD signals. We here identify and implement various coupling entities—chiral and achiral—to demonstrate chiral transfer over distances close to 100 nm. The coupling is realized by an achiral nanosphere situated between a pair of gold nanorods that are arranged far apart but in a chiral fashion using DNA origami. The transmitter particle causes a strong enhancement of the CD response, the emergence of an additional chiral feature at the resonance frequency of the nanosphere, and a redshift of the longitudinal plasmonic resonance frequency of the nanorods. Matching numerical simulations elucidate the intricate chiral optical fields in complex architectures.

Reconfigurable Plasmonic Nanostructures Controlled by DNA Origami

2020 ◽  
Vol 36 (2) ◽  
pp. 296-300
Author(s):  
Qipeng Long ◽  
Hanyang Yu ◽  
Zhe Li
Keyword(s):  
Dna Origami ◽  
Plasmonic Nanostructures

Pawilony bioniczne

BUILDER ◽  
2019 ◽  
Vol 258 (1) ◽  
pp. 26-28
Author(s):  
Anna Nowak ◽  
Wiesław Rokicki
Keyword(s):  
Fibonacci Sequence ◽  
Natural World ◽  
Digital Tools ◽  
Biological Processes ◽  
Structural Elements ◽  
Biological Models ◽  
Natural Processes ◽  
Advanced Knowledge ◽  
The Individual ◽  
Advanced Computer

INSPIRATIONS OF NATURE IN ARCHITECTURE. BIONIC PAVILIONS. The search for bionics is an interesting design notion, where the form of architectural objects is not only inspired by the aesthetics or patterns found in nature, but how its shape is reproduced by the natural processes of morphogenesis. Depending on how various patters in nature are replicated, a number of bionic modeling can be observed. The design based on the principles of forming natural structures requires some understanding of the ongoing processes and their changes. Thanks to the improvement of generative design methods allowing for the advanced knowledge in the field of technology to build the individual structural elements, a structural replication and analysis of biological processes is possible. The creation of mathematical models is an attempt to describe the forms found in the natural world, in particular the aspects of the morphogenesis. The Voronoi diagrams, or the Fibonacci sequence, which are increasingly used as a method of the discretization of the surface, deserve special consideration among the mentioned patterns found in nature. Digital tools play an important role in this process through the application of appropriate algorithms and advanced computer programs, but also experimental activities geared to building prototype solutions. The design of complicated spatial forms under different aspects is also aimed at searching for optimized technical and material solutions, in which unnecessary geometry is being eliminated. The transfer of biological models into architecture also applies to functional processes and systems found in nature in terms of shaping the coating elements. This paper is dedicated to the presentation of the completed experimental pavilions, which were created based on the bionic ideas, where the search for the multifunctional materials seems to be particularly important and could in turn revolutionize the building industry.

scholarly journals De novo sequencing and analysis of the transcriptome of two highbush blueberry (V. corymbosum L.) cultivars ‘Bluecrop’ and ‘Legacy’ at harvest and following post-harvest storage

2020 ◽  
Author(s):  
Maria Carcamo de la Concepcion ◽  
Daniel James Sargent ◽  
Nada Surbanovski ◽  
Richard Colgan ◽  
Marco Moretto
Keyword(s):  
Fruit Quality ◽  
Cold Storage ◽  
Stress Responses ◽  
De Novo ◽  
Transcript Abundance ◽  
Moisture Loss ◽  
Biological Processes ◽  
Significant Differential Expression ◽  
Post Harvest ◽  
The Individual

Abstract Background: Fruit firmness and in particular the individual components of texture and moisture loss, are considered the key quality traits when describing blueberry fruit quality, and whilst these traits are genetically regulated, the mechanisms governing their control are not clearly understood. In this investigation, RNAseq was performed on fruits of two blueberry cultivars with very different storage properties, ‘Bluecrop’ and ‘Legacy’, at harvest, three weeks storage in a non-modified environment at 4 oC and after three weeks storage at 4 oC followed by three days at 21 oC, with the aim of understanding the transcriptional changes that occur during storage in cultivars with very different post-harvest fruit quality.Results: De novo assemblies of the transcriptomes of the two cultivars were performed separately and a total of 39,335 and 41,896 unigenes for ‘Bluecrop’ and ‘Legacy’ respectively were resolved. Differential gene expression analyses were grouped into four cluster profiles based on changes in transcript abundance between harvest and 24 days post-harvest. A total of 264 unigenes were up-regulated in ‘Legacy’ and down-regulated in ‘Bluecrop’, 103 were down-regulated in ‘Legacy’ and up-regulated in ‘Bluecrop’, 43 were up-regulated in both cultivars and 355 were down-regulated in both cultivars between harvest and 24 days post-harvest. Unigenes showing significant differential expression between harvest and following post-harvest cold-storage were grouped into classes of biological processes including stress responses, cell wall metabolism, wax metabolism, calcium metabolism, cellular components, and biological processes.Conclusions: In total 21 differentially expressed unigenes with a putative role in regulating the response to post-harvest cold-storage in the two cultivars were identified from the de novo transcriptome assemblies performed. The results presented provide a stable foundation from which to perform further analyses with which to functionally validate the candidate genes identified, and to begin to understand the genetic mechanisms controlling changes in firmness in blueberry fruits post-harvest.

scholarly journals Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4798
Author(s):  
Yang Xin ◽  
Amir Ardalan Zargariantabrizi ◽  
Guido Grundmeier ◽  
Adrian Keller
Keyword(s):  
Atomic Force Microscopy ◽  
Single Molecule ◽  
Pure Water ◽  
Dna Origami ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Individual ◽  
Individual Strategies ◽  
Phosphate Buffered Saline

DNA origami nanostructures (DONs) are promising substrates for the single-molecule investigation of biomolecular reactions and dynamics by in situ atomic force microscopy (AFM). For this, they are typically immobilized on mica substrates by adding millimolar concentrations of Mg2+ ions to the sample solution, which enable the adsorption of the negatively charged DONs at the like-charged mica surface. These non-physiological Mg2+ concentrations, however, present a serious limitation in such experiments as they may interfere with the reactions and processes under investigation. Therefore, we here evaluate three approaches to efficiently immobilize DONs at mica surfaces under essentially Mg2+-free conditions. These approaches rely on the pre-adsorption of different multivalent cations, i.e., Ni2+, poly-l-lysine (PLL), and spermidine (Spdn). DON adsorption is studied in phosphate-buffered saline (PBS) and pure water. In general, Ni2+ shows the worst performance with heavily deformed DONs. For 2D DON triangles, adsorption at PLL- and in particular Spdn-modified mica may outperform even Mg2+-mediated adsorption in terms of surface coverage, depending on the employed solution. For 3D six-helix bundles, less pronounced differences between the individual strategies are observed. Our results provide some general guidance for the immobilization of DONs at mica surfaces under Mg2+-free conditions and may aid future in situ AFM studies.

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