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Bo Bao, Jason Riordon, Farshid Mostowfi, David Sinton
Microfluidic systems that leverage unique micro-scale phenomena have been developed to provide rapid, accurate and robust analysis, predominantly for biomedical applications. These attributes, in addition to the ability to access high temperatures and pressures, have motivated recent expanded applications in phase measurements relevant to industrial CO2, oil and gas applications. We here present a comprehensive review of this exciting new field, separating microfluidic and nanofluidic approaches. Microfluidics is practical, and provides similar phase properties analysis to established bulk methods with advantages in speed, control and sample size...
July 21, 2017: Lab on a Chip
Igor Bodrenko, Jiajun Wang, Samuele Salis, Mathias Winterhalter, Matteo Ceccarelli
To quantify small molecule penetration into and eventually permeation through nanopores, we applied an improved excess-noise analysis of the ion current fluctuation caused by entering molecules. The kinetic parameters of substrate entry and leave are derived from a two-state Markov model, analyzing the substrate concentration depen- dence of the average ion current and its variance. Including filter corrections allows one to detect the transition rates beyond the cutoff frequency, fc, of the instrumental ion-current filter...
July 21, 2017: ACS Sensors
Kai Tian, Ruicheng Shi, Amy Gu, Michael Pennella, Li-Qun Gu
MicroRNAs (miRNAs) are a class of noncoding RNAs that are being explored as a new type of disease biomarkers. The nanopore single-molecule sensor offers a potential noninvasive tool to detect miRNAs for diagnostics and prognosis applications. However, one of the challenges that limits its clinical applications is the presence of a large variety of nontarget nucleic acids in the biofluid extracts. Upon interacting with the nanopore, nontarget nucleic acids produce "contaminative" nanopore signals that interfere with target miRNA discrimination, thus severely lowering the accuracy in target miRNA detection...
2017: Methods in Molecular Biology
Raúl Guerrero-Avilés, Walter Orellana
The energetics and diffusion of water molecules and hydrated ions (Na(+), Cl(-)) passing through nanopores in graphene are addressed by dispersion-corrected density functional theory calculations and ab initio molecular dynamics (MD) simulations. Pores of about 0.8 nm in diameter with different pore-edge passivations, with (H) and (O, H) atoms, were considered. Our MD simulations show a water flux through the hydroxylated pores of about one H2O molecule every three picoseconds, in close agreement with recent experiments that estimated a water flux of three molecules per picosecond through pores of ∼1 nm...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
Dainelys Guadarrama Bello, Aurélien Fouillen, Antonella Badia, Antonio Nanci
While topography is a key determinant of the cellular response to biomaterials the mechanisms implicated in the cell-surface interactions are complex and still not fully elucidated. In this context, we have examined the effect of nanoscale topography on the formation of filopodia, focal adhesions, and on gene expression of proteins associated with cell adhesion and sensing. Commercially pure titanium discs were treated for oxidative nanopatterning with a solution of H2SO4/H2O2 50:50 (v/v). Scanning electron microscopy and atomic force microscopy characterizations showed that this facile chemical treatment efficiently creates a unique nanoporous surface with a root-mean-square roughness of 11...
July 17, 2017: Acta Biomaterialia
Nitin Shingne, Markus Geuss, Thomas Thurn-Albrecht, Hans-Werner Schmidt, Carmen Mijangos, Martin Steinhart, Jaime Martin
Because final properties of nanoscale polymeric structures are largely determined by the solid-state microstructure of the confined polymer, it is imperative not only to understand how the microstructure of polymers develops under nanoscale confinement but also to establish means to manipulate it. Here we present a series of processing strategies, adapted from methods used in bulk polymer processing, that allow to control the solidification of polymer materials confined in the nanopores of anodic aluminium oxide (AAO) templates...
July 20, 2017: Journal of Physical Chemistry. B
Lei Wang, Shengcai Zhu, Meikun Shen, Haiwen Tian, Songhai Xie, Hongbin Zhang, Yahong Zhang, Yi Tang
Screw dislocation structure in crystal are origin of symmetry breaking in a wide range of dense phase crystals. Preparation of such analogous structure in framework phase crystals is of great importance in zeolites but still a challenge. On the basis of crystal structure-solving and model building, we found that the two specific intergrowths in MTW zeolite produce this complex fractal and spiral structure. With the structure determined parameters (spiral pitch h, screw angle θ and spatial angle ψ) of Burgers circuit, the screw dislocation structure can be constructed by two different dimensional intergrowth sections...
July 20, 2017: Angewandte Chemie
Chao Fang, Rui Qiao
The imbibition of liquids into nanopores plays a critical role in numerous applications, and most prior studies focused on imbibition due to capillary flows. Here we report molecular simulations of the imbibition of water into single mica nanopores filled with pressurized gas. We show that, while capillary flow is suppressed by the high gas pressure, water is imbibed into the nanopore through surface hydration in the form of monolayer liquid films. As the imbibition front moves, the water film behind it gradually densifies...
July 20, 2017: Physical Chemistry Chemical Physics: PCCP
Matthew Pevarnik, Weibin Cui, Sukru Yemenicioglu, Justin Rofeh, Luke Theogarajan
Voltage gating is essential to the computational ability of neurons. We show this effect can be mimicked in a solid-state nanopore by functionalizing the pore interior with a redox active molecule. We study the integration of an active biological molecule, a quinone, into a solid state nanopore and its subsequent induced voltage gating. We show that the voltage gating effect mimics biological gating systems in its classic sigmoidal voltage response, unlike previous synthetic voltage gating systems. Initially the quinone undergoes a reduction due to radicals in the bulk solution and is converted to the hydroquinone state...
July 20, 2017: Bioinspiration & Biomimetics
Xiu Tang, Jia-Hui Zhao, Yu-Han Li, Zi-Ji Zhou, Kui Li, Fu-Tian Liu, Ya-Qian Lan
Nanoporous Co-doped Zn1-xCdxS were facilely fabricated via adopting ZIFs as templates, and Cd(NO3)2 and thiourea as precursors. The highly porous microstructure and uniform Co-doping of the photocatalyst afford a high H2-production rate (45.2 and 422.2 times larger than those of Zn0.5Cd0.5S and CdS), providing an effective way for the development of high performance nanoporous photocatalysts.
July 20, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
L E Ocola, V Sampathkumar, N Kasthuri, R P Winarski
We show that using infiltration of ZnO metal oxide can be useful for high resolution imaging of biological samples in electron and X-ray microscopy. The method is compatible with standard fixation techniques that leave the sample dry, such as finishing with super critical CO2 drying, or simple vacuum drying up to 95 °C. We demonstrate this technique can be applied on tooth and brain tissue samples. We also show that high resolution X-ray tomography can be performed on biological systems using Zn K edge (1s) absorption to enhance internal structures, and obtained the first nanoscale 10 KeV X-ray absorption images of the interior regions of a tooth...
July 19, 2017: Scientific Reports
Jingjie Sha, Hongjiao Shi, Yin Zhang, Chen Chen, Lei Liu, Yunfei Chen
As the single molecule detection tool, solid-state nanopores are being applied in more and more fields, such as medicine controlled delivery, ion conductance microscopes, nanosensors, and DNA sequencing. The critical information obtained from nanopores is the signal collected, which is the ionic block current caused by the molecules passing through the pores. However, the information collected is, in part, impeded by the relatively low signal-to-noise ratio of the current solid-state nanopore measurements. Here, we report that using a salt gradient across the nanopore could improve the signal-to-noise ratio when molecules translocate through Si3N4 nanopore...
April 28, 2017: ACS Sensors
Yoshifumi Oya, Kenji Hata, Tomonori Ohba
We present the structures of NaCl aqueous solution in carbon nanotubes with diameters of 1, 2, and 3 nm based on an analysis performed using X-ray diffraction and canonical ensemble Monte Carlo simulations. Anomalously longer nearest-neighbor distances were observed in the electrolyte for the 1-nm-diameter carbon nanotubes; in contrast, in the 2 and 3 nm carbon nanotubes, the nearest-neighbor distances were shorter than those in the bulk electrolyte. We also observed similar properties for water in carbon nanotubes, which was expected because the main component of the electrolyte was water...
July 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Chenyu Wen, Shuangshuang Zeng, Kai Arstila, Timo Sajavaara, Yu Zhu, Zhen Zhang, Shi-Li Zhang
Nanopore technology has been extensively investigated for analysis of biomolecules, and a success story in this field concerns DNA sequencing using a nanopore chip featuring an array of hundreds of biological nanopores (BioNs). Solid-state nanopores (SSNs) have been explored to attain longer lifetime and higher integration density than what BioNs can offer, but SSNs are generally considered to generate higher noise whose origin remains to be confirmed. Here, we systematically study low-frequency (including thermal and flicker) noise characteristics of SSNs measuring 7 to 200 nm in diameter drilled through a 20-nm-thick SiNx membrane by focused ion milling...
February 24, 2017: ACS Sensors
Sana Rauf, Ling Zhang, Asghar Ali, Yang Liu, Jinghong Li
Detection of very low amounts of illicit drugs such as cocaine in clinical fluids like serum continues to be important for many areas in the fight against drug trafficking. Herein, we constructed a label-free nanopore biosensor for rapid and highly sensitive detection of cocaine in human serum and saliva samples based on target-induced strand release strategy. In this bioassay, an aptamer for cocaine was prehybridized with a short complementary DNA. Owing to cocaine specific binding with aptamer, the short DNA strand was displaced from aptamer and translocation of this output DNA through α-hemolysin nanopore generated distinct spike-like current blockages...
February 24, 2017: ACS Sensors
Guanglin Xia, Qili Gao, Dalin Sun, Xuebin Yu
Fe2 O3 is regarded as a promising anode material for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its high specific capacity. The large volume change during discharge and charge processes, however, induces significant cracking of the Fe2 O3 anodes, leading to rapid fading of the capacity. Herein, a novel peapod-like nanostructured material, consisting of Fe2 O3 nanoparticles homogeneously encapsulated in the hollow interior of N-doped porous carbon nanofibers, as a high-performance anode material is reported...
July 19, 2017: Small
Yueming Zhai, Fan Zhang, Bo Zhang, Xiaohu Gao
Compared with the large variety of solid gold nanostructures, synthetic approaches for their hollow counterparts are limited, largely confined to chemical and irradiation-based etching of preformed nanostructures. In particular, the preparation of through nanopore structures is extremely challenging. Here, a unique strategy for direct synthesis of gold nanopores in solution without the need for sacrificial templates or postsynthesis processing is reported. By controlling the degree of crystal screw dislocation, a single through pore with diameter ranging from sub-nanometer to tens of nanometers, in the center of large gold nanoplates, can be engineered with precision...
July 19, 2017: Advanced Materials
Hengwei Qiu, Minqiang Wang, Zhi Yang, Shouzhen Jiang, Yanjun Liu, Le Li, Minghui Cao, Junjie Li
We present a new route for the synthesis of Ag nanopore-inlay-nanogap structures using creviced graphene-shell encapsulated Cu nanoparticles (Cu@G-NPs) as the sacrificial templates. The as-synthesized integrated Ag-core@graphene-shell@Ag-jacket nanoparticles (AgC@G@AgJ-NPs) presents "chrysanthemum" shapes that contain abundant sub-10 nm size intraparticle nanopores/nanogaps, which can generate huge enhanced electromagnetic fields to support SERS activity, resulting in an average EF > 10(7) due to a high-density of intraparticle and interparticle "hot spots"...
July 19, 2017: Chemical Communications: Chem Comm
Wenwei Sun, Jiehua Liu, Xiaoqian Liu, Xiaojing Fan, Kuan Zhou, Xiangfeng Wei
We employed a facile bimolecular (glucose and DMEA) assisted hydrothermal reaction and a solid-state reaction to obtain carbon-coated hierarchical LiTi2(PO4)3 on a large scale. The nanoporous material exhibits excellent high-rate and cycling performance owing to enhanced electronic conductivity from the ultrathin carbon layer, Ti(3+) and the shortened path for Li(+) diffusion by nanoporous frameworks.
July 19, 2017: Chemical Communications: Chem Comm
Ashley Byrne, Anna E Beaudin, Hugh E Olsen, Miten Jain, Charles Cole, Theron Palmer, Rebecca M DuBois, E Camilla Forsberg, Mark Akeson, Christopher Vollmers
Understanding gene regulation and function requires a genome-wide method capable of capturing both gene expression levels and isoform diversity at the single-cell level. Short-read RNAseq is limited in its ability to resolve complex isoforms because it fails to sequence full-length cDNA copies of RNA molecules. Here, we investigate whether RNAseq using the long-read single-molecule Oxford Nanopore MinION sequencer is able to identify and quantify complex isoforms without sacrificing accurate gene expression quantification...
July 19, 2017: Nature Communications
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