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dna nanostructure

Oscar Mendoza, Said Houmadi, Jean-Pierre Aimé, Juan Elezgaray
Logic circuits based on DNA strand displacement reaction are the basic building blocks of future nanorobotic systems. The circuits tethered to DNA origami platforms present several advantages over solution-phase versions where couplings are always diffusion-limited. Here we consider a possible implementation of one of the basic operations needed in the design of these circuits, namely, signal replication. We show that with an appropriate preparation of the initial state, signal replication performs in a reproducible way...
January 14, 2017: Journal of Chemical Physics
Phil De Luna, Sahar Mahshid, Jagotamoy Das, Binquan Luan, Edward H Sargent, Shana O Kelley, Ruhong Zhou
High-curvature electrodes facilitate rapid and sensitive detection of a broad class of molecular analytes. These sensors have reached detection limits not attained using bulk macroscale materials. It has been proposed that immobilized DNA probes are displayed at a high deflection angle on the sensor surface, allowing greater accessibility and more efficient hybridization. Here we report the first use of all-atom molecular dynamics simulations coupled with electrochemical experiments to explore the dynamics of ssDNA immobilized on high-curvature vs...
January 11, 2017: Nano Letters
Bibek Uprety, Tyler Westover, Michael Stoddard, Kamron Brinkerhoff, John Jensen, Robert C Davis, Adam T Woolley, John N Harb
An improved method for the metallization of DNA origami is examined in this work. DNA origami, a simple and robust method for creating a wide variety of nanostructured shapes and patterns, provides an enabling template for bottom-up fabrication of next-generation nanodevices. Selective metallization of these DNA templates is needed to make nanoelectronic devices. Here, we demonstrate a metallization process that uses gold nanorod seeds followed by anisotropic plating to provide improved morphology and greater control of the final metallized width of the structure...
January 11, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
J M Majikes, J A Nash, T H LaBean
Structural DNA nanotechnology has demonstrated both versatility and potential as a molecular manufacturing tool; the formation and processing of DNA nanostructures has therefore been subject to much interest. Characterization of the formation process itself is vital to understanding the role of design in production yield. We present our search for a robust new technique, chemical quenching, to arrest molecular folding in DNA systems for subsequent characterization. Toward this end we will introduce two miniM13 origami designs based on a 2...
January 11, 2017: Nanoscale
My N Bui, M Brittany Johnson, Mathias Viard, Emily Satterwhite, Angelica N Martins, Zhihai Li, Ian Marriott, Kirill A Afonin, Emil F Khisamutdinov
RNA nanotechnology employs synthetically modified ribonucleic acid (RNA) to engineer highly stable nanostructures in one, two, and three dimensions for medical applications. Despite the tremendous advantages in RNA nanotechnology, unmodified RNA itself is fragile and prone to enzymatic degradation. In contrast to use traditionally modified RNA strands e.g. 2'-fluorine, 2'-amine, 2'-methyl, we studied the effect of RNA/DNA hybrid approach utilizing a computer-assisted de novo RNA tetra-uracil (tetra-U) motif as a toolkit to address questions related to assembly efficiency, versatility, stability, and the production costs of hybrid RNA/DNA nanoparticles...
January 4, 2017: Nanomedicine: Nanotechnology, Biology, and Medicine
Pengfei Zhan, Palash K Dutta, Pengfei Wang, Gang Song, Mingjie Dai, Shu-Xia Zhao, Zhen-Gang Wang, Peng Yin, Wei Zhang, Baoquan Ding, Yonggang Ke
Distinct electromagnetic properties can emerge from the three-dimensional (3D) configuration of a plasmonic nanostructure. Furthermore, the reconfiguration of a dynamic plasmonic nanostructure, driven by physical or chemical stimuli, may generate a tailored plasmonic response. In this work, we constructed a 3D reconfigurable plasmonic nanostructure with controllable, reversible conformational transformation using bottom-up DNA self-assembly. Three gold nanorods (AuNRs) were positioned onto a reconfigurable DNA origami tripod...
January 9, 2017: ACS Nano
Cheng Tian, Hyojeong Kim, Wei Sun, Yunah Kim, Peng Yin, Haitao Liu
This paper describes the fabrication of polymer stamps using DNA nanostructure templates. This process creates stamps having diverse nanoscale features with dimensions ranging from several tens of nanometers to micrometers. DNA nanostructures including DNA nanotubes, stretched λ-DNA, two-dimensional (2D) DNA brick crystals with three-dimensional (3D) features, hexagonal DNA 2D arrays, and triangular DNA origami were used as master templates to transfer patterns to poly(methyl methacrylate) and poly(l-lactic acid) with high fidelity...
January 10, 2017: ACS Nano
Nicole A Estrich, Armando Hernandez-Garcia, Renko de Vries, Thomas H LaBean
Programmed molecular recognition is being developed for the bionanofabrication of mixed organic/inorganic supramolecular assemblies for applications in electronics, photonics, and medicine. For example, DNA-based nanotechnology seeks to exploit the easily programmed complementary base-pairing of DNA to direct assembly of complex, designed nanostructures. Optimal solution conditions for bionanofabrication, mimicking those of biological systems, may involve high concentrations of biomacromolecules (proteins, nucleic acids, etc...
January 6, 2017: ACS Nano
Yun-Liang Deng, Dang-Dang Xu, Dai-Wen Pang, Hong-Wu Tang
A three-layer core-shell nanostructure consisting of a silver core, a silica spacer, and a fluorescent dye RuBpy-doped outer silica layer was fabricated, and the optimal metal-enhanced fluorescence (MEF) distance was explored through adjusting the thickness of the silica spacer. The results show that the optimal distance is ∼10.4 nm with the maximum fluorescence enhancement factor 2.12. Then a new target-triggered MEF 'turn-on' strategy based on the optimized composite nanoparticles was successfully constructed for quantitative detection of prostate specific antigen (PSA), by using RuBpy as the energy donor and BHQ-2 as the acceptor...
January 3, 2017: Nanotechnology
Yuanchen Dong, Yuhe Renee Yang, Yiyang Zhang, Dianming Wang, Xixi Wei, Saswata Banerjee, Yan Liu, Zhongqiang Yang, Hao Yan, Dongsheng Liu
We describe the use of a frame-guided assembly (FGA) strategy to construct cuboid and dumbbell-shaped hetero-vesicles on DNA origami nanostructure scaffolds. These are achieved by varying the design of the DNA origami scaffolds that direct the distribution of the leading hydrophobic groups (LHG). By careful selection of LHGs, different types of amphiphiles (both polymer and small-molecule surfactants) were guided to form hetero-vesicles, demonstrating the versatility of the FGA strategy and its potential to construct asymmetric and dynamic hetero-vesicle assemblies with complex DNA nano-scaffolds...
December 30, 2016: Angewandte Chemie
Yuan-Cheng Zhu, Fei Xu, Nan Zhang, Wei-Wei Zhao, Jing-Juan Xu, Hong-Yuan Chen
This work reports the use of compositionally heterogeneous asymmetric Ag@Au core-satellite nanoassembly functionalized with DNA sequence as unique signaling nanoprobes for the realization of new energy-transfer-based photoelectrochemical (PEC) immunoassay of prostate- specific antigen (PSA). Specifically, the Ag@Au asymmetric core-satellite nanoassemblies (Ag@Au ACS) were fabricated on a two-dimensional glass substrate by a modified controlled assembly technique, and then functionalized with DNA sequences containing PSA aptamers as signaling nanoprobes...
December 20, 2016: Biosensors & Bioelectronics
Seong-Joong Kahng, Jong-Hoon Kim, Jae-Hyun Chung
Nanostructured tip-shaped biosensors have drawn attention for biomolecule detection as they are promising for highly sensitive and specific detection of a target analyte. Using a nanostructured tip, the sensitivity is increased to identify individual molecules because of the high aspect ratio structure. Various detection methods, such as electrochemistry, fluorescence microcopy, and Raman spectroscopy, have been attempted to enhance the sensitivity and the specificity. Due to the confined path of electrons, electrochemical measurement using a nanotip enables the detection of single molecules...
December 23, 2016: Sensors
Ziwen Dai, Hoi Man Leung, Pik Kwan Lo
Stimuli-responsive DNA-based materials represent a major class of remarkable functional nanomaterials for nano-biotechnological applications. In this review, recent progress in the development of stimuli-responsive systems based on self-assembled DNA nanostructures is introduced and classified. Representative examples are presented in terms of their design, working principles and mechanisms to trigger the response of the stimuli-responsive DNA system upon expose to a large variety of stimuli including pH, metal ions, oligonucleotides, small molecules, enzymes, heat, and light...
December 22, 2016: Small
Sung In Lim, Byungseop Yang, Younghan Jung, Jaehyun Cha, Jinhwan Cho, Eun-Sil Choi, Yong Hwan Kim, Inchan Kwon
Multistep cascade reactions in nature maximize reaction efficiency by co-assembling related enzymes. Such organization facilitates the processing of intermediates by downstream enzymes. Previously, the studies on multienzyme nanocomplexes assembled on DNA scaffolds demonstrated that closer interenzyme distance enhances the overall reaction efficiency. However, it remains unknown how the active site orientation controlled at nanoscale can have an effect on multienzyme reaction. Here, we show that controlled alignment of active sites promotes the multienzyme reaction efficiency...
December 22, 2016: Scientific Reports
Yifei Zhang, Stanislav Tsitkov, Henry Hess
A proximity effect has been invoked to explain the enhanced activity of enzyme cascades on DNA scaffolds. Using the cascade reaction carried out by glucose oxidase and horseradish peroxidase as a model system, here we study the kinetics of the cascade reaction when the enzymes are free in solution, when they are conjugated to each other and when a competing enzyme is present. No proximity effect is found, which is in agreement with models predicting that the rapidly diffusing hydrogen peroxide intermediate is well mixed...
December 22, 2016: Nature Communications
Amir Barati Farimani, Payam Dibaeinia, Narayana R Aluru
DNA origami nanostructures can be used to functionalize solid-state nanopores for single molecule studies. In this study, we characterized a nanopore in a DNA origami-graphene heterostructure for DNA detection. The DNA origami nanopore is functionalized with a specific nucleotide type at the edge of the pore. Using extensive molecular dynamics (MD) simulations, we computed and analyzed the ionic conductivity of nanopores in heterostructures carpeted with one or two layers of DNA origami on graphene. We demonstrate that a nanopore in DNA origami-graphene gives rise to distinguishable dwell times for the four DNA base types, whereas for a nanopore in bare graphene, the dwell time is almost the same for all types of bases...
December 22, 2016: ACS Applied Materials & Interfaces
Abdul M Mohammed, Petr Šulc, John Zenk, Rebecca Schulman
Within cells, nanostructures are often organized using local assembly rules that produce long-range order. Because these rules can take into account the cell's current structure and state, they can enable complexes, organelles or cytoskeletal structures to assemble around existing cellular components to form architectures. Although many methods for self-assembling biomolecular nanostructures have been developed, few can be programmed to assemble structures whose form depends on the identity and organization of structures already present in the environment...
December 19, 2016: Nature Nanotechnology
Hui Dong, Limin Zhang, Wei Liu, Yang Tian
The potential damage of Alzheimer's disease (AD) in brain function has attracted extensive attention. As the most common anion, Cl(-) has been indicated to play significant roles in brain diseases, particularly in the pathological process of AD. In this work, a label-free selective and accurate electrochemical biosensor was first developed for real-time monitoring of Cl(-) levels in a mouse brain model of AD and rat brain upon global cerebral ischemia. Silver nanoparticles (AgNPs) were designed and synthesized as selective recognition element for Cl(-), while 5'-MB-GGCGCGATTTT-SH-3' (SH-DNA-MB, MB = methylene blue) was selected as an inner reference molecule for a built-in correction to avoid the effects from the complicated brain...
December 19, 2016: ACS Chemical Neuroscience
Zhong Mei, Liang Tang
An innovative gold nanorod (GNR) array biochip was developed to systematically investigate the localized surface plasmon resonance (LSPR)-coupled fluorescence enhancement for signal amplification in molecular beacon detection. An ordered GNR assembly in vertical standing array on a glass surface was fabricated as plasmonic substrates, resulting in dramatically intensified LSPR between adjacent nanoparticles as compared to that from an ensemble of random nanorods. We have shown that the plasmonic response of the nanoarray can be tuned by the proper choice of GNR size to overlap the fluorophore excitation and emission wavelengths greater than 600 nm...
December 19, 2016: Analytical Chemistry
Xiao-Mei Shi, Gao-Chao Fan, Qingming Shen, Jun-Jie Zhu
Sensitive and accurate analysis of DNA is crucial to better understanding of DNA functions and early diagnosis of fatal disease. Herein, an enhanced photoelectrochemical (PEC) DNA biosensor was proposed based on dual-signal amplification via coupling inorganic-organic nanocomposites sensitization with λ-exonuclease (λ-Exo)-assisted target recycling. The short DNA sequence about chronic myelogenous leukemia (CML, type b3a2) was selected as target DNA (tDNA). ZnO nanoplates were deposited with CdS nanocrystals to form ZnO/CdS hetero-nanostructure, and it was used as PEC substrate for immobilizing hairpin DNA (hDNA)...
December 28, 2016: ACS Applied Materials & Interfaces
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