Solid-state Substrates Research Articles

SARS-CoV-2 Quantum Sensor Based on Nitrogen-Vacancy Centers in Diamond.

The development of highly sensitive and rapid biosensing tools targeted to the highly contagious virus SARS-CoV-2 is critical to tackling the COVID-19 pandemic. Quantum sensors can play an important role because of their superior sensitivity and fast improvements in recent years. Here we propose a molecular transducer designed for nitrogen-vacancy (NV) centers in nanodiamonds, translating the presence of SARS-CoV-2 RNA into an unambiguous magnetic noise signal that can be optically read out. We evaluate the performance of the hybrid sensor, including its sensitivity and false negative rate, and compare it to widespread diagnostic methods. The proposed method is fast and promises to reach a sensitivity down to a few hundreds of RNA copies with false negative rate less than 1%. The proposed hybrid sensor can be further implemented with different solid-state defects and substrates, generalized to diagnose other RNA viruses, and integrated with CRISPR technology.

Efficacy of "PESTA" Granular Formulation Myco-herbicides of Aspergillus niger spores in Striga hermonthica (Del.) Benth Biocontrol

Aspergillus niger spores were isolated from diseased Striga plants at the Demonstration Farm Faculty of Agriculture, Shambat was used as a mycoherbicide for the biocontrol of Striga hermothica plant.Sterilized dried sorghum straw, Alfalafa hay and sucrose were used, as solid state substrates for growth and multiplication. These were used in different formulations coated to sorghum seeds or mixed with soil or added after Striga emergence to spores of Aspergillus niger .The results indicated that the formulation camposed of %07sterilized sorghum straw , %57 alfalfa hay formulation and 57sucrose was the best as it yielded the highest number of spores as compared to other formulations. Therefore, this formulation was selected for further application and was applied for inoculation of Striga seeds in the presence of its host (sorghum) seeds in different ways in the glass house at Shambat, Faculty of Agriculture.

Rim Binding of Cyclodextrins in Size-Sensitive Guest Recognition.

Cyclodextrins (CDs) are doughnut-shaped cyclic oligosaccharides having a cavity and two rims. Inclusion binding in the cavity has long served as a classic model of molecular recognition, and rim binding has been neglected. We found that CDs recognize guests by size-sensitive binding using the two rims in addition to the cavity, using single-molecule electron microscopy and a library of graphitic cones as a solid-state substrate for complexation. For example, with its cavity and rim binding ability combined, γ-CD can recognize a guest of radius between 4 and 9 Å with a size-recognition precision of better than 1 Å, as shown by structural analysis of thousands of individual specimens and statistical analysis of the data thereof. A 2.5 ms resolution electron microscopic video provided direct evidence of the process of size recognition. The data suggest the occurrence of the rim binding mode for guests larger than the size of the CD cavity and illustrate a unique application of dynamic molecular electron microscopy for deciphering the spatiotemporal details of supramolecular events.

Light-Driven Magnetic Encoding for Hybrid Magnetic Micromachines.

Remote manipulation of a micromachine under an external magnetic field is significant in a variety of applications. However, magnetic manipulation requires that either the target objects or the fluids should be ferromagnetic or superparamagnetic. To extend the applicability, we propose a versatile optical printing technique termed femtosecond laser-directed bubble microprinting (FsLDBM) for on-demand magnetic encoding. Harnessing Marangoni convection, evaporation flow, and capillary force for long-distance delivery, near-field attraction, and printing, respectively, FsLDBM is capable of printing nanomaterials on the solid-state substrate made of arbitrary materials. As a proof-of-concept, we actuate a 3D polymer microturbine under a rotating magnetic field by implementing γ-Fe2O3 nanomagnets on its blade. Moreover, we demonstrate the magnetic encoding on a living daphnia and versatile manipulation of the hybrid daphnia. With its general applicability, the FsLDBM approach provides opportunities for magnetic control of general microstructures in a variety of applications, such as smart microbots and biological microsurgery.

Nanostructuring of honeycomb-like polystyrene with excimer laser

This paper is aimed on the construction of honeycomb like patterns (HCP) with defined dimensions of pores on activated solid-state substrate. Dip coating technique with improved phase separation was used for pattern preparation, subsequent nanostructuring was realized with an excimer laser. Polystyrene patterns were prepared on perfluorethylenepropylene, which were subsequently treated with laser wavelength 248 nm. The main goal was to prepare honeycomb like pattern and by interaction of such microstructure with an excimer laser to prepare superposed structure. This idea was fully fulfilled, uniform micropattern on perfluorinated polymer was prepared, with several laser fluences and number of pulses to be tested subsequently. Optimal conditions of KrF exposure were determined to be 6000 pulses and interval of laser treatment from 8 to 16 mJ.cm−2, by this combination of input parameters a superposed globular nanostructure was constructed on honeycomb-like polystyrene microstructure. Surface wettability, morphology and chemistry of nanopatterned microstructures were changed significantly, oxygen concentration of treated substrates was significantly increased. Particular stages of globular pattern formation were studied and described in detail by atomic force microscopy, scanning electron microscopy, EDS/EDX and XPS analysis. Elemental mapping was applied for detailed analysis of prepared superposed pattern.

Yellow mombin and jackfruit seeds residues applied in the production of reducing sugars by a crude multi‐enzymatic extract produced by Penicillium roqueforti ATCC 101110

As an alternative to the use of widely investigated agro-industrial residues, the present study aimed to promote the valorization of two selected residues, yellow mombin seed (YS) and jackfruit seed (JS), as a result of their enhanced performance. YS was applied as a solid state substrate for Penicillium roqueforti ATCC 101110 cultivation (25 °C, Aw = 0.963, 107 spores g-1 and 142 h) to produce a crude multi-enzymatic extract (CE-YS) containing activities of CMCase = 31.95 U g-1 , xylanase = 56.85 U g-1 , exoglucanase = 5.55 U g-1 and FPase = 24.60 U g-1 . CE-YS was then applied to six different residues saccharification and the best performance was obtained with jackfruit seed residue (JS), which was selected for enzymatic saccharification. The highest productivity of reducing sugars expressed as glucose (6.26 mg g-1 h-1 ) was obtained under the conditions: 40.7 g L-1 JS, 5 mmol L-1 MgCl2 , 65 °C, 120 rpm, pH 3.0 (citrate buffer 50 mmol L-1 ) and 18 h. The residues, YS and JS, can be used satisfactorily for the production of bioproducts of great industrial applicability, such as crude extracts (containing cellulolytic enzymes) and RS (which can be converted, for example, into bioethanol). © 2020 Society of Chemical Industry.

Adsorption of Polar Molecules on a Solid Substrate

Abstract—A simple scheme for estimating the adsorption energy of polar molecules on solid state substrates has been proposed within the Harrison bond orbitals method. Analytical expressions are obtained for the ionic and metallic components of the adsorption energy for diatomic and tetraatomic molecules. The adsorption of GaCl and AlCl3 on a semiconductor substrate is considered as an example.

Flexible organic field-effect transistor arrays for wearable neuromorphic device applications.

With the advent of wearable microelectronic devices in the interdisciplinary bio-electronics research field, synaptic devices with capability of neuromorphic computing are attracting more and more attention as the building blocks for the next generation computing structure. Conventional flash-like synaptic transistors are built on rigid solid-state substrates, and the inorganic materials and the high-temperature processing steps have severely limited their applications in various flexible electronic devices and systems. Here, flexible organic flash-like synaptic devices have been fabricated on a flexible substrate with the organic C8-BTBT as the conducting channel. The device exhibits a memory window greater than 20 V and excellent synaptic functions including short/long-term synaptic plasticity and spike-timing-dependent plasticity. In addition, even under the bending condition (7 mm bending radius), the transistor can still stably achieve a variety of synaptic functions. This work shows that low-temperature processing technology with the integration of organic materials can pave a promising pathway for the realization of flexible synaptic systems and the future development of wearable electronic devices.

The Solid Fermentation State’s Optimization of Trichoderma Harzianum M1

In order to exploitation a solid inoculant of Trichoderma harzianum Ml which has a significant effect on Gramineae pasture, so that it can be better in the production of the application, the solid-state fermentation substrate was optimized in this experiment. The optimal combination of the solid-state fermentation of Trichoderma harzianum Ml was screened by single factor and orthogonal experiment. The effects of carbon, nitrogen and inorganic salt on the sporulation quantity of Trichoderma harzianum M1 were further studied. The results showed that: The optimal substrate for the solid-state fermentation of Trichoderma harzianum was the ratio of grass powder: wheat bran: rice bran was 3: 2: 1, the optimal carbon source was glucose, the optimal nitrogen source was peptone, and the optimal inorganic salt was dipotassium hydrogen phosphate. Therefore, the optimal formula of Trichoderma harzianum M1 solid-state fermentation substrate was as follows: the ratio of grass powder: wheat bran: rice bran was 3: 2: 1, glucose 1%, peptone 0.05%, dipotassium hydrogen phosphate 0.01%, the number of sporulation up to 5.9×109cfu/g.

Fluid surface coatings for solid-state nanopores: comparison of phospholipid bilayers and archaea-inspired lipid monolayers

In the context of sensing and characterizing single proteins with synthetic nanopores, lipid bilayer coatings provide at least four benefits: first, they minimize unwanted protein adhesion to the pore walls by exposing a zwitterionic, fluid surface. Second, they can slow down protein translocation and rotation by the opportunity to tether proteins with a lipid anchor to the fluid bilayer coating. Third, they provide the possibility to impart analyte specificity by including lipid anchors with a specific receptor or ligand in the coating. Fourth, they offer a method for tuning nanopore diameters by choice of the length of the lipid’s acyl chains. The work presented here compares four properties of various lipid compositions with regard to their suitability as nanopore coatings for protein sensing experiments: (1) electrical noise during current recordings through solid-state nanopores before and after lipid coating, (2) long-term stability of the recorded current baseline and, by inference, of the coating, (3) viscosity of the coating as quantified by the lateral diffusion coefficient of lipids in the coating, and (4) the success rate of generating a suitable coating for quantitative nanopore-based resistive pulse recordings. We surveyed lipid coatings prepared from bolaamphiphilic, monolayer-forming lipids inspired by extremophile archaea and compared them to typical bilayer-forming phosphatidylcholine lipids containing various fractions of curvature-inducing lipids or cholesterol. We found that coatings from archaea-inspired lipids provide several advantages compared to conventional phospholipids; the stable, low noise baseline qualities and high viscosity make these membranes especially suitable for analysis that estimates physical protein parameters such as the net charge of proteins as they enable translocation events with sufficiently long duration to time-resolve dwell time distributions completely. The work presented here reveals that the ease or difficulty of coating a nanopore with lipid membranes did not depend significantly on the composition of the lipid mixture, but rather on the geometry and surface chemistry of the nanopore in the solid state substrate. In particular, annealing substrates containing the nanopore increased the success rate of generating stable lipid coatings.

DNA translocation through a nanopore in an ultrathin self-assembled peptide membrane

Here, we explore the possibility of using peptide-based materials as a membrane in solid-state nanopore devices in an effort to develop a sequence-specific, programmable biological membrane platform. We use a recently developed tyrosine-mediated self-assembly peptide sheet. At the air/water interface, the 5mer peptide YFCFY self-assembles into a uniform and robust two-dimensional (2D) structure, and the peptide sheet is easily transferred to a low-noise glass substrate. The thickness of the peptide membrane can be adjusted to approximately 5 nm (or even to 2 nm) by an etching process, and the diameters of the peptide nanopores can be precisely controlled using a focused electron beam with an attuned spot size. The ionic current noise of the peptide nanopore is comparable to those of typical silicon nitride nanopores or multilayer 2D materials. Using this membrane, we successfully observe translocation of 1000 bp double-stranded DNA with a sufficient signal-to-noise ratio of ∼30 and an elongated translocation speed of ∼1 bp μs−1. Our results suggest that the self-assembled peptide film can be used as a sensitive nanopore membrane and employed as a platform for applying biological functionalities to solid-state substrates.

Nanopore-Based Confined Spaces for Single-Molecular Analysis.

The field of nanopore sensing at the single-molecular level is in a "boom" period. Such nanopores, which are either composed of biological materials or are fabricated from solid-state substrates, offer a unique confined space that is compatible with the single-molecular scale. Under the influence of an electrical field, such single-biomolecular interfaces can read single-molecular information and, if appropriately fine-tuned, each molecule plays its individual ionic rhythm to compose a "molecular symphony". Over the past few decades, many research groups have worked on nanopore-based single-molecular sensors for a range of thrilling chemical and clinical applications. Furthermore, for the past decade, we have also focused on nanopore-based sensors. In this Minireview, we summarize the recent developments in fundamental research and applications in this area, along with data algorithms and advances in hardware, which act as infrastructure for the electrochemical analysis.

Surface-enhanced Raman scattering of subwavelength metallic structures

Surface-enhanced Raman scattering (SERS) makes the Raman signals, as fingerprints of different vibration modes of chemical bonds, significant in practical applications. Two main mechanisms, chemical and physical, are attributed to the SERS of molecules adsorbed on metals. The physical mechanism plays a major role in SERS, which is the focus of our paper. Recent SERS systems are mostly based on dimer structures, i.e. nanoparticle pairs, of noble metals. Large amplification of electrical field occurs in the gap of a dimer structure compared with a single nanoparticle. The above gap positions are called as " hot spots” of SERS. In addition, the reproducibility and reliability of SERS substrates are also important for practical applications. Here we use periodical subwavelength metallic structures to meet such needs, and develop other kinds of electrical field enhancement mechanisms. We present the electrical field enhancement of the band-edge mode of surface plasmon polariton, gap plasmon polariton mode, as well as their coupling mode. We choose one-dimensional subwavelength metallic structures to clarify the physical mechanism. Our purpose is to develop subwavelength metallic structures with even and intensive " hot spots”, serving as ultrasensitive solid-state SERS substrates with excellent reproducibility and reliability.

Extraction, characterization and antioxidant activity analysis of the polysaccharide from the solid-state fermentation substrate of Inonotus hispidus

A polysaccharide from Inonotus hispidus was prepared by solid-state fermentation (SSF), and an efficient ultrasound-assisted extraction method was used to optimize the extraction process of Inonotus hispidus solid-state fermentation polysaccharide (IHSFP). The optimal extraction parameters were as follows: solid-liquid ratio of 1:40, ultrasound time of 34 min, ultrasound power of 350 W and ultrasound temperature of 70 °C. The yield of IHSFP was 51.06 ± 0.34% under the optimal conditions. Two types of polysaccharide fractions (IHSFP-1 and IHSFP-2) were isolated by DEAE-52 and Sephadex G-200 columns. IHSFP-2 had stronger antioxidant activity than IHSFP-1, and it can reduce H2O2-induced oxidative damage to cells in vitro. Therefore, the properties of IHSFP-2 were further characterized. The results showed that the molecular weight of IHSFP-2 was 14.44 kDa, it was composed of glucose (Glc), mannose (Man), galactose (Gal), glucuronic acid (GlcUA), galactosamine (GalN), arabinose (Ara) and ribose (Rib), and the contents of these monosaccharides were 51%, 21%, 20%, 3%, 2%, 2% and 1%, respectively. The results of this study may contribute to the efficient production of the polysaccharide of Inonotus hispidus, and provide new ideas for its application in functional foods and cosmetics.

Controllable Synthesis of Circular Graphene Domains By Atmosphere Pressure Chemical Vapor Deposition

Graphene, as a perfect two-dimensional crystalline structure, has attracted much attention in the research community, owing its unusual mechanical strength (>1Pa), optical transparency and high carrier mobility for various promising applications. Several methods have been used to develop to obtain graphene, such as mechanical exfoliation, thermal decomposition of SiC and chemical vapor deposition (CVD). Among these methods, CVD is considered to be the most promising way for graphene industrial development and scale-up production due to its convenience and economic efficiency. In a CVD process, growth on Cu substrates is particularly attractive since the growth occurs via a self-limiting mechanism, attributed to the negligible carbon solubility in copper. Yet the CVD graphene shows a lower carrier mobility of a few hundred to a few thousand cm2/(Vs) compared with exfoliated graphene obtained from natural graphite, because of the presence of growth defects and boundaries. In order to attain the predicted theoretical values for graphene, it is critical to improve graphene film quality. Previous studies have shown that seamless merging of graphene domains during CVD is an ideal route to reducing defects and domain boundaries, and produce single crystal graphene to enable further applications. Furthermore, the morphology and edge structure of individual graphene domains strongly influence its properties. It is very important to understand the nucleation stage and the expansion mechanism of the graphene domains to control the morphology of graphene films. Recent advances in the CVD method yields various interesting graphene domain shapes. Pentagonal, triangular, rectangular, snow-like graphene, twelve-pointed and four-lobed, graphene domains have been successfully obtained. The various shapes of these graphene domains can be achieved by optimizing growth parameters, such as precursor composition, flux, and choice of substrate. However, all of these methods either require liquid-state copper as the substrate or yield irregular circular or other shapes with one or very few separate circular graphene domain. Hence, it would be quite advantageous to grow graphene on a solid-state copper substrate via the simultaneous large scale growth and seamless merging of circular-shaped graphene domains. This provides a very good platform to observe and investigate the growth mechanism leading to large area single crystal graphene sheets. In this presentation, I will report the first successful large-scale growth of single-crystal “circular” graphene domains on a solid-state copper substrate during the early stage of CVD operated under atmosphere pressure. The individual circular graphene domains have smooth edges as well as axisymmetric and centrosymmetric shapes which permit seamless merging of adjacent graphene without the effect of orientation. Figure 1

Opto-Thermophoretic Manipulation and Construction of Colloidal Superstructures in Photocurable Hydrogels

Light-based manipulation of colloidal particles holds great promise in fabrication of functional devices. Construction of complex colloidal superstructures using traditional optical tweezers is limited by high operation power and strong heating effect. Herein, we demonstrate low-power opto-thermophoretic manipulation and construction of colloidal superstructures in photocurable hydrogels. By introducing cationic surfactants into a hydrogel solution under a light-directed temperature field, we create both thermoelectric fields and depletion attraction forces to control the suspended colloidal particles. The particles of various sizes and compositions are thus trapped and organized into various superstructures. Furthermore, the colloidal superstructures are immobilized and patterned onto solid-state substrates through UV-induced photopolymerization of the hydrogel. Our opto-thermophoretic technique will open up avenues for bottom-up assembly of colloidal materials and devices.

Electronic Structure and Spin Transport Properties of a New Class of Semiconductor Surface-Confined One-Dimensional Half-Metallic [Eu-(CnHn–2)]N (n = 7–9) Sandwich Compounds and Molecular Wires: First Principle Studies

Transition-metal atom/π-conjugated ring sandwich compounds are promising candidates for application in molecular spintronics. However, a great challenge that has significantly restrained the practical application of these sandwich compounds is their fabrication on a well-characterized solid-state substrate in a controllable manner. In this work, we suggested a two-step self-assemble way to fabricate the Eu-CnHn–2 compounds on the hydrogen-terminated Si(100) surface and theoretically studied the geometric structure and electronic and magnetic properties. Theoretical results indicate that the silicon surface is an ideal substrate to support such kind of metal atom-encapsulated sandwich compounds as the lattice distance of silicon (100) surface is close to the inter-ring distances of freestanding gas-phase sandwich compounds. On the basis of the spin-polarized density functional theory calculations and ab initio molecular dynamics simulations, we find that the silicon surface-supported Si-[EuCh]N, Si-[EuCOT]N, and Si-[EuCnt]N sandwich compounds all process a ferromagnetic ground state. Moreover, the cycloheptatrienyl (Ch) and cyclononatetraenyl (Cnt) Eu sandwich compounds show half-metallic properties. The calculation of electron/spin transport properties using the nonequilibrium Green’s-function method confirms that the Ch Eu sandwich compounds are excellent spin filters, and the spin filter efficiency (SFE) is independent of the cluster size (N), whereas the SFE of Si-[EuCOT]N decreases rapidly with the increase of cluster size. The perfect half-metallic properties of these surface-supported sandwich compounds are promising for future application in spin devices. The present work suggests a way to fabricate the half-metallic sandwich compounds on a semiconductor silicon surface.

Anisotropic Nanoscale Wrinkling in Solid-State Substrates.

Pattern formation induced by wrinkling is a very common phenomenon exhibited in soft-matter substrates. In all these systems, wrinkles develop in the presence of compressively stressed thin films lying on compliant substrates. Here, the controlled growth of self-organized nanopatterns exploiting a wrinkling instability on a solid-state substrate is demonstrated. Soda-lime glasses are modified in the surface layers by a defocused ion beam, which triggers the formation of a compressively stressed surface layer deprived of alkali ions. When the substrate is heated up near its glass transition temperature, the wrinkling instability boosts the growth rate of the pattern by about two orders of magnitude. High-aspect-ratio anisotropic ripples bound by faceted ridges are thus formed, which represent an optimal template for guiding the growth of large-area arrays of functional nanostructures. The engineering over large square centimeter areas of quasi-1D arrays of Au nanostripe dimers endowed with tunable plasmonic response, strong optical dichroism, and high electrical conductivity is demonstrated. These peculiar functionalities allow these large-area substrates to be exploited as active metamaterials in nanophotonics, biosensing, and optoelectronics.

Tetrapyrrolic Surface Coatings for Applications in Photoelectrosynthetic Fuel Production

Hybrid materials capable of linking light capture and conversion technologies with the ability to drive reductive chemical transformations are attractive as components in photoelectrosynthetic cells. [1] We have recently reported methods of applying molecular surface coatings composed of metalloporphyrin redox catalysts onto solid-state substrates that are either conductive or semi-conductive. [2-5] The metalloporphyrin catalysts used in this work are capable of activating electrochemical transformations including the conversion of protons to hydrogen and carbon dioxide to carbon monoxide. In one approach, metalloporphyrin precursors are prepared via a novel synthetic strategy to yield a macrocycle with a pendent 4-vinylphenyl surface attachment group at the beta-position of the porphyrin ring structure. [2] This modification allows use of a photo-induced immobilization chemistry to attach intact metalloporphyrins to a range of (semi)conducting surfaces. In addition, we have shown that initial application of thin-film polymer surface coatings can provide a molecular interface for assembling metalloporphyrin catalysts in a subsequent wet chemical treatment step. [3] In this presentation, spectroscopic characterization of these materials coupled with electrochemical analysis will be presented. These findings offer an improved understanding of the structure and function relationships governing this class of materials. A. M. Beiler, D. Khusnutdinova, S. I. Jacob, G. F. Moore, Ind. & Eng. Chem. Research , 55 , 5306-5314 (2016); DOI: 10.1021/acs.iecr.6b00478D. Khusnutdinova, A. M. Beiler, B. L. Wadsworth, S. I. Jacob, G. F. Moore, Chem. Sci., 8, 253-259 (2017); DOI: 10.1039/c6sc02664hA. M. Beiler, D. Khusnutdinova, B. L. Wadsworth, G. F. Moore, Inorg. Chem. , 56, 12178 (2017); DOI: 10.1021/acs.inorgchem.7b01509A. M. Beiler, D. Khusnutdinova, S. I. Jacob, G. F. Moore, ACS Appl. Mater. Interfaces , 8, 10038-10043 (2016); DOI: 10.1021/acsami.6b01557B. L. Wadsworth, A. M. Beiler, D. Khusnutdinova, S. I. Jacob, G. F. Moore, ACS Catal. 6, 8048-8057 (2016); DOI: 10.1021/acscatal.6b02194 Figure 1

Laser-assisted spalling of large-area semiconductor and solid state substrates

Abstract