scholarly journals Boron-Implanted Silicon Substrates for Physical Adsorption of DNA Origami

2018 ◽  
Vol 19 (9) ◽  
pp. 2513 ◽  
Author(s):  
Sadao Takabayashi ◽  
Shohei Kotani ◽  
Juan Flores-Estrada ◽  
Elijah Spears ◽  
Jennifer E. Padilla ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
Physical Adsorption ◽  
High Surface ◽  
Dna Origami ◽  
Silicon Substrates ◽  
Dna Nanostructures ◽  
Solution Ph ◽  
Chemical Functionalization ◽  
Industry Standard ◽  
Controlled Adsorption

DNA nanostructures routinely self-assemble with sub-10 nm feature sizes. This capability has created industry interest in using DNA as a lithographic mask, yet with few exceptions, solution-based deposition of DNA nanostructures has remained primarily academic to date. En route to controlled adsorption of DNA patterns onto manufactured substrates, deposition and placement of DNA origami has been demonstrated on chemically functionalized silicon substrates. While compelling, chemical functionalization adds fabrication complexity that limits mask efficiency and hence industry adoption. As an alternative, we developed an ion implantation process that tailors the surface potential of silicon substrates to facilitate adsorption of DNA nanostructures without the need for chemical functionalization. Industry standard 300 mm silicon wafers were processed, and we showed controlled adsorption of DNA origami onto boron-implanted silicon patterns; selective to a surrounding silicon oxide matrix. The hydrophilic substrate achieves very high surface selectivity by exploiting pH-dependent protonation of silanol-groups on silicon dioxide (SiO2), across a range of solution pH values and magnesium chloride (MgCl2) buffer concentrations.

Physical adsorption and surface diffusion of DNA origami onto boron-implanted silicon substrates

2017 ◽  
Author(s):  
Sadao Takabayashi ◽  
Shohei Kotani ◽  
Juan Flores-Estrada ◽  
Jennifer E. Padilla ◽  
Lizandra C. Godwin ◽  
...  
Keyword(s):  
Surface Diffusion ◽  
Physical Adsorption ◽  
Dna Origami ◽  
Silicon Substrates

Interface effects in the formation of silicon oxide on metal silicide layers over silicon substrates

1983 ◽  
Vol 54 (4) ◽  
pp. 1849-1854 ◽  
Author(s):  
J. E. E. Baglin ◽  
F. M. d’Heurle ◽  
C. S. Petersson
Keyword(s):  
Silicon Oxide ◽  
Silicon Substrates ◽  
Metal Silicide ◽  
Interface Effects

scholarly journals Quaternization of Poly(2-diethyl aminoethyl methacrylate) Brush-Grafted Magnetic Mesoporous Nanoparticles Using 2-Iodoethanol for Removing Anionic Dyes

2021 ◽  
Vol 11 (21) ◽  
pp. 10451
Author(s):  
Khalid Mohammed Alotaibi ◽  
Abdurrahman A. Almethen ◽  
Abeer M. Beagan ◽  
Hassan M. Al-Swaidan ◽  
Ashfaq Ahmad ◽  
...  
Keyword(s):  
Mesoporous Silica Nanoparticles ◽  
High Surface ◽  
High Surface Area ◽  
Polymer Chains ◽  
Sunset Yellow ◽  
Anionic Dyes ◽  
Solution Ph ◽  
Effects Of Ph ◽  
Weak Adsorption ◽  
Ph Level

Magnetic mesoporous silica nanoparticles (Fe3O4-MSNs) were successfully synthesized with a relatively high surface area of 568 m2g−1. Fe3O4-MSNs were then modified with poly(2-diethyl aminoethyl methacrylate) (PDEAEMA) brushes using surface-initiated ARGET atom transfer radical polymerization (ATRP) (Fe3O4@MSN-PDMAEMA). Since the charge of PDEAEMA is externally regulated by solution pH, tertiary amines in the polymer chains were quaternized using 2-iodoethanol to obtain cationic polymer chains with a permanent positive charge (Fe3O4@MSN-QPDMAEMA). The intensity of the C−O peak in the C1s X-ray photoelectron spectrum increased after reaction with 2-iodoethanol, suggesting that the quaternization process was successful. The applicability of the synthesized materials on the removal of methyl orange (MO), and sunset yellow (E110) dyes from an aqueous solution was examined. The effects of pH, contact time, and initial dyes concentrations on the removal performance were investigated by batch experiments. The results showed that the Fe3O4@MSN-PDMAEMA sample exhibited a weak adsorption performance toward both MO and E110, compared with Fe3O4@MSN-QPDMAEMA at a pH level above 5. The maximum adsorption capacities of MO and E110 using Fe3O4@MSN-QPDMAEMA were 294 mg g−1 and 194.8 mg g−1, respectively.

scholarly journals Biophysical characterization of DNA origami nanostructures reveals inaccessibility to intercalation binding sites

2019 ◽  
Author(s):  
Helen L. Miller ◽  
Sonia Contera ◽  
Adam J.M. Wollman ◽  
Adam Hirst ◽  
Katherine E. Dunn ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Single Molecule ◽  
Targeted Drug Delivery ◽  
Binding Sites ◽  
Dna Origami ◽  
Target Cells ◽  
Dna Nanostructures ◽  
Synthetic Dna ◽  
Drug Molecules ◽  
Targeted Drug

AbstractIntercalation of drug molecules into synthetic DNA nanostructures formed through self-assembled origami has been postulated as a valuable future method for targeted drug delivery. This is due to the excellent biocompatibility of synthetic DNA nanostructures, and high potential for flexible programmability including facile drug release into or near to target cells. Such favourable properties may enable high initial loading and efficient release for a predictable number of drug molecules per nanostructure carrier, important for efficient delivery of safe and effective drug doses to minimise non-specific release away from target cells. However, basic questions remain as to how intercalation-mediated loading depends on the DNA carrier structure. Here we use the interaction of dyes YOYO-1 and acridine orange with a tightly-packed 2D DNA origami tile as a simple model system to investigate intercalation-mediated loading. We employed multiple biophysical techniques including single-molecule fluorescence microscopy, atomic force microscopy, gel electrophoresis and controllable damage using low temperature plasma on synthetic DNA origami samples. Our results indicate that not all potential DNA binding sites are accessible for dye intercalation, which has implications for future DNA nanostructures designed for targeted drug delivery.

scholarly journals Preparation of MoS2 nano-corals by hydrothermal method for adsorption of tartrazine in the aqueous medium

2020 ◽  
Vol 9 (4) ◽  
pp. 93-99
Author(s):  
Hung Mac Van ◽  
Tuan Vu Anh
Keyword(s):  
Adsorption Capacity ◽  
Hydrothermal Method ◽  
Adsorption Kinetics ◽  
Organic Dyes ◽  
Nile Blue ◽  
High Surface ◽  
High Surface Area ◽  
Optimal Dosage ◽  
Solution Ph ◽  
Intra Particle Diffusion

Corals-like molybdenum disulfide (MoS2) have been successfully synthesized via the hydrothermal method. The as-prepared MoS2 material with a high surface area of 83.9 m2.g-1 was used for the removal of tartrazine from an aqueous solution. The effects of parameters including contact time, MoS2 dosage, and solution pH on adsorption capacity were studied. The optimal dosage of MoS2 for removing tartrazine was 0.08 g and the removal efficiency of tartrazine reached 81.5 % for 100 min of adsorption. The adsorption kinetics studies were carried out using pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. The results showed that the pseudo-second-kinetic model better described the adsorption kinetics of tartrazine on MoS2 and film diffusion was the rate-limiting step. In addition, the adsorption capacity of MoS2 was also performed with various organic dyes such as nile blue, janus green B, and congo red.

scholarly journals DNA Origami Nanomachines

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1766 ◽  
Author(s):  
Masayuki Endo ◽  
Hiroshi Sugiyama
Keyword(s):  
Dna Sequences ◽  
Molecular Motors ◽  
Molecular Machines ◽  
Dna Origami ◽  
Dna Nanostructures ◽  
Molecular Systems ◽  
Nanoscale Structures ◽  
Research Fields ◽  
Dna Strands ◽  
External Stimuli

DNA can assemble various molecules and nanomaterials in a programmed fashion and is a powerful tool in the nanotechnology and biology research fields. DNA also allows the construction of desired nanoscale structures via the design of DNA sequences. Structural nanotechnology, especially DNA origami, is widely used to design and create functionalized nanostructures and devices. In addition, DNA molecular machines have been created and are operated by specific DNA strands and external stimuli to perform linear, rotational, and reciprocating movements. Furthermore, complicated molecular systems have been created on DNA nanostructures by arranging multiple molecules and molecular machines precisely to mimic biological systems. Currently, DNA nanomachines, such as molecular motors, are operated on DNA nanostructures. Dynamic DNA nanostructures that have a mechanically controllable system have also been developed. In this review, we describe recent research on new DNA nanomachines and nanosystems that were built on designed DNA nanostructures.

scholarly journals Adsorption of pharmaceuticals from aqueous solutions using biochar derived from cotton gin waste and guayule bagasse

Biochar ◽  
2020 ◽  
Author(s):  
Marlene C. Ndoun ◽  
Herschel A. Elliott ◽  
Heather E. Preisendanz ◽  
Clinton F. Williams ◽  
Allan Knopf ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
High Surface ◽  
Strong Interactions ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Cotton Gin Waste ◽  
Cotton Gin

Abstract Biochars produced from cotton gin waste (CG) and guayule bagasse (GB) were characterized and explored as potential adsorbents for the removal of pharmaceuticals (sulfapyridine-SPY, docusate-DCT and erythromycin-ETM) from aqueous solution. An increase in biochar pyrolysis temperature from 350 οC to 700 οC led to an increase in pH, specific surface area, and surface hydrophobicity. The electronegative surface of all tested biochars indicated that non-Coulombic mechanisms were involved in adsorption of the anionic or uncharged pharmaceuticals under experimental conditions. The adsorption capacities of Sulfapyridine (SPY), Docusate (DCT) and Erythromycin (ETM) on biochar were influenced by the contact time and solution pH, as well as biochar specific surface area and functional groups. Adsorption of these pharmaceutical compounds was dominated by a complex interplay of three mechanisms: hydrophobic partitioning, hydrogen bonding and π–π electron donor–acceptor (EDA) interactions. Despite weaker π–π EDA interactions, reduced hydrophobicity of SPY− and increased electrostatic repulsion between anionic SPY− and the electronegative CG biochar surface at higher pH, the adsorption of SPY unexpectedly increased from 40% to 70% with an increase in pH from 7 to 10. Under alkaline conditions, adsorption was dominated by the formation of strong negative charge-assisted H-bonding between the sulfonamide moiety of SPY and surface carboxylic groups. There seemed to be no appreciable and consistent differences in the extent of DCT and ETM adsorption as the pH changed. Results suggest the CG and GB biochars could act as effective adsorbents for the removal of pharmaceuticals from reclaimed water prior to irrigation. High surface area biochars with physico-chemical properties (e.g., presence of functional groups, high cation and anion exchange capacities) conducive to strong interactions with polar-nonpolar functionality of pharmaceuticals could be used to achieve significant contaminant removal from water. Graphic Abstract

scholarly journals Adsorption of Tea Polyphenols using Microporous Starch: A Study of Kinetics, Equilibrium and Thermodynamics

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1449 ◽  
Author(s):  
Xianchun Hu ◽  
Xianfeng Du
Keyword(s):  
Physical Adsorption ◽  
Tea Polyphenols ◽  
Adsorptive Capacity ◽  
Partial Hydrolysis ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Long Term Storage ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

Microporous starch (MPS) granules were formed by the partial hydrolysis of starch using α–amylase and glucoamylase. Due to its biodegradability and safety, MPS was employed to adsorb tea polyphenols (TPS) based on their microporous characteristics. The influences of solution pH, time, initial concentration and temperature on the adsorptive capacity were investigated. The adsorption kinetics data conformed to the pseudo second–order kinetics model, and the equilibrium adsorption data were well described by the Langmuir isotherm model. According to the fitting of the adsorption isotherm formula, the maximum adsorption capacity of TPS onto MPS at pH 6.7 and T = 293 K was approximately 63.1 mg/g. The thermodynamic parameters suggested that the adsorption of TPS onto MPS was spontaneous and exothermic. Fourier transform infrared (FT–IR) analysis and the thermodynamics data were consistent with a physical adsorption mechanism. In addition, MPS-loaded TPS had better stability during long-term storage at ambient temperature.

The real-time rendering of subdivision surfaces using hardware tessellation

2015 ◽  
Vol 57 (5) ◽  
Author(s):  
Matthias Nießner
Keyword(s):  
Real Time ◽  
High Surface ◽  
Subdivision Surfaces ◽  
High Surface Quality ◽  
Industry Standard ◽  
Desktop Computers ◽  
Computational Budget ◽  
Film Productions ◽  
Novel Algorithms

AbstractIn the last decade, computer-generated images have become a vital and integral part of our everyday lives. The quality of these images depends considerably on the geometric representation of the underlying virtual 3D environments. Subdivision surfaces, one such representation, have been found to be very useful due to their unique geometric properties. These properties led to the adaptation of subdivision surfaces as a movie industry standard for modeling 3D geometry, making subdivision surfaces indispensable in today's film productions. However, despite the high surface quality of subdivision surfaces, the complexity of underlying calculations requires a significant computational budget. In this thesis, we address this problem and propose novel algorithms to accelerate the evaluation of subdivision surfaces by several orders of magnitude. This enables the rendering of high-quality movie content on commercially available desktop computers within only a few milliseconds, opening up the possibility of using subdivision surfaces in real-time applications (e. g., video games). The results of this work have been made publicly available in Pixar's open source initiative

Wet-chemical treatment and electronic interface properties of silicon solar cell substrates

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Heike Angermann ◽  
Jörg Rappich ◽  
Carola Klimm
Keyword(s):  
Solar Cell ◽  
Light Trapping ◽  
High Surface ◽  
Interface State ◽  
Silicon Substrates ◽  
Chemical Treatments ◽  
Interface Recombination ◽  
Wet Chemical ◽  
Substrate Surfaces

AbstractOn textured n-type silicon substrates for solar cell manufacturing, the relation between light trapping behavior, structural imperfections, energetic distribution of interface state densities and interface recombination losses were investigated by applying surface sensitive techniques. The field-modulated surface photovoltage (SPV), in-situ photoluminescence (PL) measurements, total hemispherical UV-NIR-reflectance measurements and electron microscopy (SEM) were employed to yield detailed information on the influence of wet-chemical treatments on preparation induced micro-roughness and electronic properties of polished and textured silicon substrates. It was shown that isotropic as well as anisotropic etching of light trapping structures result in high surface micro-roughness and density of interface states. Removing damaged surface layers in the nm range by wet-chemical treatments, the density of these states and the related interface recombination loss can be reduced. In-situ PL measurements were applied to optimise HF-treatment times aimed at undamaged, oxide-free and hydrogen-terminated substrate surfaces as starting material for subsequent solar cell preparations.

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