Read by QxMD icon Read

ACS Nano

Yujing Ma, Sadhu Kolekar, Horacio Coy Diaz, Johannes Aprojanz, Ilio Miccoli, Christoph Tegenkamp, Matthias Batzill
Twin grain boundaries in MoSe2 are metallic and undergo a metal to insulator Peierls transition at low temperature. Growth of MoSe2 by molecular beam epitaxy results in the spontaneous formation of a high density of these twin grain boundaries, likely as a mechanism to incorporation Se-deficiency in the film. Using scanning tunneling microscopy, we study the grain boundary network that is formed in homoepitaxially grown MoSe2, and for MoSe2 grown heteroepitaxially on MoS2- and HOPG- substrates. No statistically relevant variation of the grain boundary concentration has been found for the different substrates, indicating that the grain boundary formation is substrate independent and depends mainly on the growth conditions...
April 28, 2017: ACS Nano
Cameron L C Smith, Anil H Thilsted, Jonas N Pedersen, Tomas H Youngman, Julia C Dyrnum, Nicolai A Michaelsen, Rodolphe Marie, Anders Kristensen
The ability to handle single, free molecules in lab-on-a-chip systems is key to the development of advanced biotechnologies. Entropic confinement offers passive control of polymers in nanofluidic systems by locally asserting a molecule's number of available conformation states through structured landscapes. Separately, a range of plasmonic configurations have demonstrated active manipulation of nano-objects by harnessing concentrated electric fields. The integration of these two independent techniques promises a range of sophisticated and complementary functions to handle, for example, DNA, but numerous difficulties, in particular, conflicting requirements of channel size, have prevented progress...
April 28, 2017: ACS Nano
Carolin Vietz, Izabela Kaminska, Maria Sanz Paz, Philip Tinnefeld, Guillermo P Acuna
Plasmonic structures are known to affect the fluorescence properties of dyes placed in close proximity. This effect has been exploited in combination with single-molecule techniques for several applications in the field of biosensing. Among these plasmonic structures, top-down zero-mode waveguides stand out due to their broadband capabilities. In contrast, optical antennas based on gold nanostructures exhibit fluorescence enhancement on a narrow fraction of the visible spectrum typically restricted to the red to near-infrared region...
April 28, 2017: ACS Nano
Saranshu Singla, Emmanuel Anim-Danso, Ahmad E Islam, Yen Ngo, Steve S Kim, Rajesh R Naik, Ali Dhinojwala
The graphene/water interface has received considerable attention in the past decade due to its relevance in various potential applications including energy storage, sensing, desalination, and catalysis. Most of our knowledge about the interfacial water structure next to graphene stems from simulations, which use experimentally measured water contact angle (WCA) on graphene (or graphite) to estimate the water-graphene interaction strength. However, the existence of a wide spectrum of reported WCAs on supported graphene and graphitic surfaces makes it difficult to interpret the water-graphene interactions...
April 27, 2017: ACS Nano
Ying-Chu Chen, Hongta Yang
The octopus is able to adhere to slippery, fouled and irregular surfaces in the marine intertidal environment, because of its periodic infundibulum-shaped suckers on the arms. Here, we report a scalable self-assembly technique for fabricating adhesion materials that mimic octopus-sucker functionality. By utilizing spin-coated two-dimensional colloidal crystals as templates, non-close-packed nanosucker arrays are patterned on silicone substrates. The resulting nanosuckers can be deformed to exhibit great adhesive capacities on both micro-rough and flat surfaces in dry and wet environments...
April 27, 2017: ACS Nano
Christian Godau, Thomas Kämpfe, Andreas Thiessen, Lukas M Eng, Alexander Haußmann
Domain walls (DWs) in ferroelectric/ferroic materials have been in the central research focus for the last 50 years; DWs bear a multitude of extraordinary physical parameters within a unit-cell-sized lateral confinement. Especially, one outstanding feature has recently attracted a lot of attention for room-temperature applications, which is the potential to use DWs as 2-dimensional (2D) conducting channels that completely penetrate bulk compounds. Domain wall currents in lithium niobate (LNO) so far lie in the lower $pA$ regime...
April 27, 2017: ACS Nano
Ahmed Ghedjatti, Yann Magnin, Frédéric Fossard, Guillaume Wang, Hakim Amara, Emmanuel Flahaut, Jean-Sebastien Lauret, Annick Loiseau
Structural identification of double-walled carbon nanotubes (DWNT) is presented through a robust procedure based on the latest generation of transmission electron microscope, making possible a statistical analysis based on numerous nano-objects. This approach reveals that inner and outer tubes of DWNTs are not randomly oriented, suggesting the existence of a mechanical coupling between the two concentric walls. With the support of atomic-scale modeling, we attribute it to the presence of incommensurate domains whose structures depend on the diameters and helicities of both tubes, and where inner tubes try to achieve a local stacking orientation to reduce strain effects...
April 27, 2017: ACS Nano
Feng Wu, Yusheng Ye, Jia-Qi Huang, Teng Zhao, Ji Qian, Yuanyuan Zhao, Li Li, Lei Wei, Rui Luo, Yongxin Huang, Yi Xing, Renjie Chen
The behavior of two-dimensional (2D) materials for energy-storage systems relates to their morphology and physicochemical properties. Although various 2D materials can be found in different fields, the open access of these materials has greatly hampered their practical applications, such as in lithium sulfur batteries, where the soluble intermediates should be controlled. Here, we have developed a facile approach to prepare 2D ultra-thin interconnected carbon fabrics (ICFs) with "bubble-like" morphology and abundant mesopores using a "blowing bubble" method...
April 27, 2017: ACS Nano
Anagh Bhaumik, Ritesh Sachan, Jagdish Narayan
We report high-temperature superconductivity in B-doped amorphous quenched carbon (Q-carbon). This phase is formed after nanosecond laser melting of B-doped amorphous carbon films in a super undercooled state and followed by rapid quenching. Magnetic susceptibility measurements show the characteristics of type-II Bardeen-Cooper-Schrieffer superconductivity with a superconducting transition temperature (Tc) of 36.0±0.5 K for 17.0±1.0 atomic percent boron concentration. This value is significantly higher than the best experimentally reported Tc of 11 K for crystalline B-doped diamond...
April 27, 2017: ACS Nano
Nifang Zhao, Miao Yang, Qian Zhao, Weiwei Gao, Tao Xie, Hao Bai
Through designing hierarchical structures, particularly optimizing the chemical and architectural interactions at its inorganic/organic interface, nacre has achieved an excellent combination of contradictory mechanical properties such as strength and toughness, which is highly demanded yet difficult to achieve by most synthetic materials. Most techniques applied to develop nacre-mimetic composites have been focused on mimicking the "brick-and-mortar" structure, but the interfacial architectural features, especially the asperities and mineral bridges of "bricks", have been rarely concerned, which are of equal importance for enhancing mechanical properties of nacre...
April 27, 2017: ACS Nano
Ziyi Cheng, Namhyun Choi, Rui Wang, Sangyeop Lee, Kyung Chul Moon, Soo-Young Yoon, Lingxin Chen, Jaebum Choo
Accurate analysis of specific biomarkers in clinical serum is essential for early diagnosis and treatment of cancer. Here, a surface-enhanced Raman scattering (SERS)-based immunoassay, using magnetic beads and SERS nano tags, was developed for the determination of free to total (f/t) prostate specific antigen (PSA) ratio to improve the diagnostic performance of prostate cancer. To assess the clinical applicability of the proposed method, SERS-based assays for the simultaneous detection of dual PSA markers, free PSA (f-PSA) and complexed PSA (c-PSA), were performed for clinical samples in the gray zone between 4...
April 27, 2017: ACS Nano
Wei Chen, Guohao Wang, Bryant C Yung, Gang Liu, Zhiyong Qian, Xiaoyuan Chen
Exendin-4 has been clinically exploited for treating type 2 diabetes, but the short circulation half-life and multiple daily injections limit its widespread application with respect to poor patient compliance, low efficacy, and high treatment cost. In this study, a potent long-acting release system based on biomimetic mineralization was constructed for biocompatible and sustained exendin-4 delivery. Similar to natural biomineralization, exendin-4 can be mineralized to form nanosized mineral solids by means of the reaction between acidic amino acid residues and calcium ions in a supersaturated environment with negligible influence on peptide bioactivity...
April 27, 2017: ACS Nano
Ortal Lidor-Shalev, Nikolaos Pliatsikas, Yacov Carmiel, Panos Patsalas, Yitzhak Mastai
In this article, we describe an advance approach for the fabrication of chiral metal-oxide nanofilms. Our approach is based on the atomic layer deposition of titania and alumina nanofilms onto cellulose microfibers, used as chiral templates, leading to the formation of chiral nanofilms with a spatial fibrous structure. The chiral nanofilms were extensively characterized by X-ray photoelectron spectroscopy and high-resolution electron microscopy. The chiral property of the produced titania nanofilms was studied by enantioselective adsorption experiments using circular-dichroism spectroscopy and chiral high-performance liquid chromatography...
April 27, 2017: ACS Nano
Eric R Meshot, Darwin W Zwissler, Ngoc Bui, Tevye R Kuykendall, Cheng Wang, Alexander Hexemer, Kuang Jen J Wu, Francesco Fornasiero
Fundamental understanding of structure-property relationships in hierarchically organized nanostructures is crucial for the development of new functionality, yet quantifying structure across multiple length scales is challenging. In this work, we used nondestructive X-ray scattering to quantitatively map the multiscale structure of hierarchically self-organized carbon nanotube (CNT) "forests" across 4 orders of magnitude in length scale, from 2.0 Å to 1.5 μm. Fully resolved structural features include the graphitic honeycomb lattice and interlayer walls (atomic), CNT diameter (nano), as well as the greater CNT ensemble (meso) and large corrugations (micro)...
April 27, 2017: ACS Nano
Beate Reiser, Dominik Gerstner, Lola Gonzalez-Garcia, Johannes H M Maurer, Ioannis Kanelidis, Tobias Kraus
Hierarchical structures lend strength to natural fibers made of soft nanoscale building blocks. Intermolecular interactions connect the components at different levels of hierarchy, distribute stresses, and guarantee structural integrity under load. Here, we show that synthetic ultrathin gold nanowires with interacting ligand shells can be spun into biomimetic, free-standing microfibers. A solution spinning process first aligns the wires, then lets their ligand shells interact, and finally converts them into a hierarchical superstructure...
April 26, 2017: ACS Nano
Mark R Miller, Jennifer B Raftis, Jeremy P Langrish, Steven G McLean, Pawitrabhorn Samutrtai, Shea P Connell, Simon Wilson, Alex T Vesey, Paul H B Fokkens, A John F Boere, Petra Krystek, Colin J Campbell, Patrick W F Hadoke, Ken Donaldson, Flemming R Cassee, David E Newby, Rodger Duffin, Nicholas L Mills
The development of engineered nanomaterials is growing exponentially, despite concerns over their potential similarities to environmental nanoparticles that are associated with significant cardiorespiratory morbidity and mortality. The mechanisms through which inhalation of nanoparticles could trigger acute cardiovascular events are emerging, but a fundamental unanswered question remains: Do inhaled nanoparticles translocate from the lung in man and directly contribute to the pathogenesis of cardiovascular disease? In complementary clinical and experimental studies, we used gold nanoparticles to evaluate particle translocation, permitting detection by high-resolution inductively coupled mass spectrometry and Raman microscopy...
April 26, 2017: ACS Nano
Yuan Ping, Dawei Ding, Ricardo A N S Ramos, Harini Mohanram, Kanagavel Deepankumar, Jianqing Gao, Guping Tang, Ali Miserez
Suckerin proteins, recently discovered in the sucker ring teeth of squids, represent a family of promising structural biomacromolecules that can form supramolecular networks stabilized by nanoconfined β-sheets. Exploiting this feature as well as their specific amino acid composition, we demonstrate that artificial suckerin-19 (S-19) can be engineered into nanocarriers for efficient drug delivery and gene transfection in vitro and in vivo. First, we demonstrate that S-19 self-assembles into β-sheet stabilized nanoparticles with controlled particle sizes of 100-200 nm that are able to encapsulate hydrophobic drugs for pH-dependent release in vitro, and that can effectively inhibit tumor growth in vivo...
April 26, 2017: ACS Nano
Dunfeng Gao, Ioannis Zegkinoglou, Nuria J Divins, Fabian Scholten, Ilya Sinev, Philipp Grosse, Beatriz Roldan Cuenya
Carbon dioxide electroreduction to chemicals and fuels powered by renewable energy sources is considered a promising path to address climate change and energy storage needs. We have developed highly active and selective copper (Cu) nanocube catalysts with tunable Cu(100) facet and oxygen/chlorine ion content by low-pressure plasma pre-treatments. These catalysts display lower overpotentials and higher ethylene, ethanol and n-propanol selectivity, resulting in a maximum Faradaic efficiency (FE) of ~73% for C2 and C3 products...
April 25, 2017: ACS Nano
Sanjay Behura, Phong Nguyen, Rousan Debbarma, Songwei Che, Michael R Seacrist, Vikas Berry
Hexagonal boron nitride (h-BN) is an ideal platform for interfacing with two-dimensional (2D) nanomaterials to reduce carrier scattering for high-quality 2D electronics. However, scalable, transfer-free growth of hexagonal boron nitride (h-BN) remains a challenge. Currently, h-BN based 2D heterostructures require exfoliation or chemical transfer of h-BN grown on metals resulting in small areas or significant interfacial impurities. Here, we demonstrate a surface-chemistry influenced transfer-free growth of large-area, uniform, and smooth h-BN directly on silicon (Si)-based substrates including Si, silicon nitride (Si3N4), and silicon dioxide (SiO2) via low-pressure chemical vapor deposition...
April 25, 2017: ACS Nano
Rajaprakash Ramachandramoorthy, Yanming Wang, Amin Aghaei, Gunther Richter, Wei Cai, Horacio D Espinosa
Time-dependent mechanical characterization of nanowires is critical to understand their long-term reliability in applications such as flexible-electronics and touch screens. It is also of great importance to develop a theoretical framework for experimentation and analysis on the mechanics of nanowires under time-dependent loading conditions such as stress-relaxation and fatigue. Here, we combine in situ scanning electron microscope (SEM)/transmission electron microscope (TEM) tests with atomistic and phase-field simulations to understand the deformation mechanisms of single crystal silver nanowires held under constant strain...
April 24, 2017: ACS Nano
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"