Nanopores

This paper deals with the effect of interface structures on the mechanical properties of fiber reinforced composite materials. First, the background of research, development and applications on hybrid composite materials is introduced. Second, metal/polymer composite bonded structures are discussed. Then, the rationale is given for nanostructuring the interface in composite materials and structures by introducing nanoscale features such as nanopores and nanofibers. The effects of modifying matrices and nano-architecturing interfaces on the mechanical properties of nanocomposite materials are examined. A nonlinear damage model for characterizing the deformation behavior of polymeric nanocomposites is presented and the application of this model to carbon nanotube-reinforced and reactive graphite nanotube-reinforced epoxy composite materials is shown.

study focuses on the preparation of thermoplastic polyurethane (TPU) nanocomposite using Vietnamese montmorillonite (MMT) as the reinforced phase. The MMT was previously modified by intercalating polyethylene oxide (PEO) and polyvinyl alcohol (PVA) molecules between the clay layers. X-ray diffraction (XRD) results of organoclays revealed that galleries of MMT were increased to 18. A and 2 A after their intercalation with PEO and PVA, respectively. Thermoplastic polyurethane (TPU) nanocomposites composed of 1, 3, 5, and 7%wt organoclays were synthesized. The result of XRD and transmission electron microscopic (TEM) analyses implied that the PEO modified MMT was well dispersed, at 3%wt, in polyurethane matrix. Fourier Transform Infrared Spectroscopic (FTIR) has confirmed this result by showing the hydrogenous interaction between the urethane linkage and OH group on the surface of silicate layer. Thermogravimetric (TG) showed that the organoclay samples also presented improved thermal ...

The aim of this study is to confirm the formation of inclusion complexes between miconazole (MCZ) and two derivatives of beta-cyclodextrin, methyl-beta-cyclodextrin (MβCD) and 2-hydroxypropyl-beta-cyclodextrin (HPβCD) in aqueous solution by phase solubility studies. Inclusion complexes with MβCD in the solid state were then prepared by different methods, i.e., kneading, coevaporation (COE), spray-drying (SD), and lyophilization (LPh). The physicochemical properties of these complexes were subsequently studied by means of differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction techniques. Phase solubility diagrams with MβCD and HPβCD were classified as AP type, indicating the formation of 1:1 and 1:2 stoichiometric inclusion complexes. The apparent stability constants (KS) calculated from the phase solubility diagram were 145.69 M−1 (K 1:1) and 11.11 M−1 (K 1:2) for MβCD and 126.94 M−1 (K 1:1) and 2.20 M−1 (K 1:2...

Solid-state nanopore-based sensors are promising platforms for next-generation sequencing technologies, featuring label-free single-molecule sensitivity, rapid detection, and low-cost manufacturing. In recent years, solid-state nanopores have been explored due to their miscellaneous fabrication methods and their use in a wide range of sensing applications. Here, we highlight a novel family of solid-state nanopores which have recently appeared, namely plasmonic nanopores. The use of plasmonic nanopores to engineer electromagnetic fields around a nanopore sensor allows for enhanced optical spectroscopies, local control over temperature, thermophoresis of molecules and ions to/from the sensor, and trapping of entities. This Mini Review offers a comprehensive understanding of the current state-of-the-art plasmonic nano-pores for single-molecule detection and biomolecular sequencing applications and discusses the latest advances and future perspectives on plasmonic nanopore-based technologies. S urface plasmon resonance (SPR) refers to the collective oscillations of the conduction electrons in metallic nanostructures. 1 Both the intensity and the energy of the SPR phenomenon strongly depend on the size, shape, and composition of the nanostructures, as well as on the dielectric properties of the surrounding environment. Various factors affect the plasmonic nanostructure response, which allow for a rationally guided design of plasmonic sensors with tunable sensitivity. These nanoscale detectors have found applications in several fields such as light harvesting, photocatalysis, subwavelength imaging, metamaterials, and nanomedicine. 2 Among others, one specific family of plasmonic platforms is based on plasmonic nanohole arrays and the more recently implemented plasmonic nanopores, sub-100 nm apertures connecting two compartments, for sensing applications. Although the reader can find exhaustive details on the principles, fabrication, and applications of plasmonic nanoholes and nanopores for biosensing in recent reviews by Dahlin 3 and by Spitzberg and co-workers, 4 here we focus our attention on the potential applications and integration of plasmonic nanopores as transducers in single-molecule detection, manipulation, and sequencing. During the last few decades a new generation of single-molecule information reader technologies have emerged, the most advanced example being single-molecule sequencing (SMS). 5 SMS involves threading single nucleic acid strands through elements (reader molecules, enzymes, nanopores, and other nanostructures) that can be used for detecting specific signals (e.g., electrical, optical, or mechanical). Individual base pairs, the monomer units of DNA/RNA polymers, are then detected sequentially one at a time as they interact with these elements. In particular, in the past several years SMS platforms, such as those by Pacific Biosciences and Oxford Nanopore Technologies, have become available to researchers and are currently being utilized in research and clinical settings. SMS nanotechnologies can be divided into two main categories: (i) Sequencing-by-synthesis in which a DNA polymerase repli-cates a DNA molecule and the added sequence is read out, either in real time 6 or by sequential addition of bases, 7 and (ii) nanopore-sequencing technologies in which single molecules of DNA (or RNA) are threaded through a nanopore or positioned in the vicinity of a nanopore, and k-mers of DNA bases (k = 4−5) are detected as they are translocated through the pore in single base steps. 8,9 However, nucleic acid sequencing goes beyond the four DNA/RNA bases, as various chemical modifications and damaged DNA sites produce additional signals that require orthogonal readout modes for correct modified base assignment. Therefore, at the core of nanopore sequencing technologies lies a challenge of producing solid-state nanopores with a quality that rivals their much more reliable biological pore counterparts. In particular, ion channels and bacterial toxin channels, for

Structural genomic variants form a common type of genetic alteration underlying human genetic disease and phenotypic variation. Despite major improvements in genome sequencing technology and data analysis, the detection of structural variants still poses challenges, particularly when variants are of high complexity. Emerging long-read single-molecule sequencing technologies provide new opportunities for detection of structural variants. Here, we demonstrate sequencing of the genomes of two patients with congenital abnormalities using the ONT MinION at 11x and 16x mean coverage, respectively. We developed a bioinformatic pipeline - NanoSV - to efficiently map genomic structural variants (SVs) from the long-read data. We demonstrate that the nanopore data are superior to corresponding short-read data with regard to detection of de novo rearrangements originating from complex chromothripsis events in the patients. Additionally, genome-wide surveillance of SVs, revealed 3,253 (33%) nove...

This review summarizes the importance of nanoporous materials and their fascinating structural properties with respect to the catalytic and photocatalytic reduction of CO2 to methane, toward achieving a sustainable energy supply. The importance of catalysis as a bridge step for advanced energy systems and the associated environmental issues are stressed. A deep understanding of the fundamentals of these nanoporous solids is necessary to improve the design and efficiency of CO2 methanation. The role of the support dominates the design in terms of developing an efficient methanation catalyst, specifically with respect to ensuring enhanced metal dispersion and a long catalyst lifetime. Nanoporous materials provide the best supports for Ni, Ru, Rh, Co, Fe particles because they can prevent sintering and deactivation through coking, which otherwise blocks the metal surface as carbon accumulates. This review concludes with the major challenges facing the CO2 methanation by nanoporous mate...

Plasmonic nanopores are the subject of extensive investigations as a potential platform to enable efficient optical readout in translocation experiments with biomolecules such as DNA and proteins. They allow for the engineering of electromagnetic fields at the nanoscale, which are typically used to enhance the emission efficiency of fluorescent molecules. Their features make them suitable for detection strategies based on the energy transfer between translocating molecules and the nanopore itself. Here, we carry out an optical experiment to show that a handful of diffusing dyes acting as donors can exchange energy via Förster-resonance energy transfer (FRET) with a gold nanopore functionalized with dyes behaving as acceptors. The FRET pair is composed of ATTORho6G (donor) and Alexa610 (acceptor). To perform this proof-of-concept experiment, we use a gold nanopore with a diameter of 80 nm, prepared on a Si 3 N 4 membrane. We observe that the presence of the acceptors on the walls of the nanopore reduces the lifetime of the diffusing donors. In addition, we observe that the presence of the acceptors reduces the fluorescence signal on the donor detection channel and increases the fluorescence signal on the acceptor detection channel. The combination of these three effects gives us enough evidence to claim that the diffusing donors exchange energy with the functionalized nanopore via FRET, despite the relatively large size of the nanopore. The FRET efficiency of the process is found to be of the order of 30%, which is in fairly good agreement with a theoretical value obtained using a simplified model.

Nanopore-based sequencing techniques can reconstruct properties of biosequences by analyzing the sequence-dependent ionic current steps produced as biomolecules pass through a pore. Typically this involves alignment of new data to a reference, where both reference construction and alignment have been performed by hand. We propose an automated method for aligning nanopore data to a reference through the use of hidden Markov models. Several features that arise from prior processing steps and from the class of enzyme used can be simply incorporated into the model. Previously, the M2MspA nanopore was shown to be sensitive enough to distinguish between cytosine, methylcytosine and hydroxymethylcytosine. We validated our automated methodology on a subset of that data by automatically calculating an error rate for the distinction between the three cytosine variants and show that the automated methodology produces a 2-3% error rate, lower than the 10% error rate from previous manual segment...