Substrate Preparation Research Articles

Cost-effective and highly selective paper-based potentiometric thiocyanate nanosensor employing nanocomposite for substrate preparation

Cost-effective and highly selective paper-based potentiometric thiocyanate nanosensor employing nanocomposite for substrate preparation

Gold-grafted melamine sponge as surface-enhanced Raman spectroscopy substrate for enzyme-linked immunoassay of mycotoxins in cereal samples.

Gold-grafted melamine sponge (AuSp) was fabricated and applied as surface-enhanced Raman spectroscopy (SERS) substrate for enzyme-linked immunoassay of 2 typical mycotoxins, zearalenone (ZEN) and T-2 toxin. The gold nanoparticles were in situ grown on the sponge, and the product showed good effect in enhancing Raman signal and good stability. COMSOL and Gaussian simulations were used to analyze the enhancing effect. Some of the experimental conditions that may affect the determination results were studied in order to meet the maximum response to mycotoxins. At optimized conditions, the limits of detection of the method were 1μg·kg-1 and 0.05μg·kg-1 for ZEN and T-2 toxin, with linear ranges of 5-100μg·kg-1 and 0.1-20μg·kg-1, respectively, and relative standard deviations lower than 7.0%. The established method was used to determine ZEN and T-2 toxin in six kinds of cereal samples, the recoveries were 85-120%, and relative errors were less than 13.0%. These results indicated the accuracy of the established method. After 1-year storage, signal strength of AuSp for mycotoxins determination decreased by less than 10%, showing stability over a long time. Our work provided a new method for SERS determination of mycotoxins, which reduces the complexity of substrate preparation and the sample consumption compared with traditional methods, and thus has potential for on-line SERS determination.

Comparative studies on interfacial bond performance of ultrahigh performance concrete (UHPC) for sustainable repair of bridges and pavements

Ultra high performance concrete (UHPC) is emerging as an innovative sustainable solution to rehabilitate deteriorated concrete pavements and bridges. In such usage, UHPC may be cast against different substrate materials such as normal strength concrete (NSC) for bridge strengthening and rehabilitation or against high strength concrete (HSC) for shear key connections. UHPC may also be cast against precast UHPC due to the rapid increase in using precast UHPC components. Although the UHPC usage in above applications has recently increased, an investigation of bond performance between UHPC and three different substrate materials have not yet been investigated. The study examined the bond performance between cast-in-place UHPC and three different substrate materials. Three different surface preparations were considered in the current study: smooth, exposed aggregate/fibers and grooved. To generalize the outcomes from the present study, three different test methods including, splitting, bi-shear and slant shear with three different slants were selected. The experimental results demonstrated that the UHPC adhered better with NSC and HSC substrates when the pressure washing was used to expose the aggregate. Meanwhile, the UHPC had better bond with grooved surface preparation of UHPC substrate. The smooth surface should be avoided when UHPC cast against all substrates. Furthermore, the friction coefficients from the codes were overestimated for smooth surface regardless the substrate strengths. However, the design codes provided a conservative estimate for both cohesion and friction coefficients for exposed aggregate/fibers and grooved interface surface preparations.

Preparation and characterization of temperature-induced ultrasensitive SERS large-scale vertical Au nanosphere dimers

Plasmonic dimers have a very wide range of applications as a unique platform for studying the fundamental effects of plasmonics. Most dimer structures are prepared by chemical methods and direct-writing methods, such as coupling agents and lithography. These methods are often complex and expensive. Here, we prepared Au nanospheres (AuNSs) by layer-by-layer (LBL) deposition, used polymethyl methacrylate (PMMA) as a spacer layer, and then annealed the deposited AuNSs to orient the assembly and integrate them together. In this paper, suitable PMMA spin coating conditions and optimal annealing temperatures were explored, and large-scale AuNSs-PMMA-AuNSs(NSs-P-NSs) composed of vertical Au nanosphere dimers were prepared successfully. The detection limits of this substrate can reach 4 × 10−12 M/L and 4 × 10−10 M/L for Rhodamine 6 G (R6G) and Crystal Violet (CV), respectively, demonstrating excellent Raman activity. In addition, the sensitivity of detecting aspartame (APM) is 0.015625 g/L. This method is not only simple to operate but also allows the preparation of a large-scale uniform substrate with excellent detection capabilities.

Molecularly imprinted sensors based on highly stretchable electrospun membranes for cortisol detection

Cortisol is a stress-sensitive glucocorticoid that is a key indicator of the body’s physical and mental health. However, current detection methods often suffer from issues such as high cost, complexity, and inability to monitor in real time. Combining molecular imprinting (MIP) technology with flexible substrate preparation technology to prepare wearable sensors on fiber membranes is a feasible solution for achieving low-cost, fast, and real-time monitoring. In this article, we integrated a flexible wearable MIP sensor on the TPU fiber membrane prepared by an electrospinning method for monitoring cortisol molecules. Then the composite material of MXene nanosheets and Carbon nanotubes (CNTs) is assembled onto a fiber membrane by spraying to form a working electrode. The three-dimensional interconnected conductive network, high specific surface area, and high conductivity significantly improve the sensing performance of electrodes, and the linear detection range of the MIP cortisol electrochemical sensor can reach 0.417 nM-1.28 μM. It is also effective in distinguishing cortisol from other interfering substances. TPU fiber membranes can be combined with fabrics, thus providing a material basis for the realization of portable, wearable, and fast-detecting cortisol sensors.

A Tuneable and Easy-to-Prepare SERS Substrate Based on Ag Nanorods: A Versatile Tool for Solution and Dry-State Analyses.

Surface-enhanced Raman spectroscopy is a powerful technique for the ultra-sensitive detection of organic analytes. In this paper, the preparation of SERS substrates based on silver nanorods (AgNRs) is proposed, exploiting a simple protocol which does not require complex procedures and/or sophisticated and expensive instrumentation. For this purpose, various syntheses of AgNRs were tested, and the best one for preparing the SERS active substrate proved to be the one which does not involve surfactants as nanoparticle stabilizers. The plasmonic properties of the selected substrate can be modified based on the concentration of the deposited nanoparticles, allowing for the experimentation of different excitation wavelengths. Positive results were obtained on reference solutions of three natural dyes of historical interest using both green exciting radiation (532 nm) and two near-infrared ones (785 and 850 nm; the latter is combined with the SSE™ technology for further fluorescence quenching). Furthermore, the substrates of AgNRs were found to be suitable for SERS measurements even in dry-state conditions, i.e., only exploiting the electromagnetic interaction between the nanostructured substrate and the dye molecules absorbed onto a wool fibre.

Preparation of 99.6 % alumina ceramic substrates with high thermal conductivity by tape casting and warm pressing process

High-purity alumina ceramic substrates have drawn immense attention because of its high strength and hardness, as well as good chemical stability. However, the high sintering temperature and low product yield are significant barriers to the preparation of high-purity alumina ceramic substrates. In this study, modified alumina nanoparticles are used to fabricate high-purity alumina ceramic substrates under pressureless sintering via a tape casting–warm pressing process. The influences of powder modification, forming processes, sintering temperature, and powder particle size on the microstructure, mechanical properties, and thermal properties of the fabricated alumina ceramic substrates are investigated. The experimental results show that tape casting–warm pressing significantly improves the microstructure and density of the green tape and ceramic substrate. As the particle size decreases from 1 μm to 100 nm, the grain arrangement of the ceramic substrate gradually becomes more compact. The smooth ceramic substrate prepared with 100 nm modified powders achieves a relative density of 98.85 % when sintered at 1550 °C, while the average roughness is only 20.0 nm. Especially, the 99.6 % alumina ceramic substrate exhibits excellent physical and mechanical properties, with a thermal conductivity of 37.39 W/(m·K) and fracture toughness of 4.68 MPa m1/2, making it highly suitable for application in the power integrated-circuit field.

Band Alignment and Surface Photo-Voltage Analysis of C-Si/Siox/Poly-Silicon Passivating-Contact Stacks Through X-Ray Photoelectron Spectroscopy.

Ultrathin SiOx layers and c-Si/SiOx interfaces find application in tunnel-oxide passivated contacts (TOPcon) for high-efficiency silicon solar cells. Here, we investigate their detailed microscopic properties, with specific attention for the case of c-Si(100) substrates, capped either by p-type or n-type poly-silicon layers [c-Si/SiOx/poly-Si (p+) or c-Si/SiOx/poly-Si (n+)]. Our focus is on the effects of the substrate preparation conditions (either by a dry-plasma or wet SiOx process) and the high-temperature annealing step (as required for the poly-Si crystallization) on the SiOx stoichiometry and its microscopic structure. Through advanced photoemission techniques, we find a clearly decreased valence band offset between the c-Si and SiOx (from 4.5 eV to 4.15 eV) when comparing the dry SiOx with the wet SiOx process, independent of the SiOx film thickness, but correlating with the relative fraction of sub-stochiometric Si states. We lastly examine the magnitude of band-bending of the contact structure through controlled in-situ exposure to light of the surfaces and subsequent tracking of core and valence band levels via a surface photovoltage and a junction photo-voltage (JPV) effect. By analyzing this JPV effect qualitatively, we find it to be proportional to the expected quasi fermi level splitting within the c-Si wafer.

Twin-free thermal laser epitaxy of Si on sapphire

The heteroepitaxial growth of silicon (Si) is essential for modern electronics. Our study investigates the potential of thermal laser epitaxy (TLE) for Si epitaxy. A systematic study on the evaporation behavior of Si during TLE identifies and addresses the causes of notable flux rate fluctuations, resulting in a Si flux with ±0.3% stability over time. We also demonstrate heteroepitaxy of Si on c-plane sapphire substrates via TLE. High-temperature substrate preparation combined with deposition at a substrate temperature of 1000 °C produced high-quality epitaxial Si (111) films without twin domains.

Optimization of Manure-Based Substrate Preparation to Reduce Nutrients Losses and Improve Quality for Growth of Agaricus bisporus

With the growing world population, food demand has also increased, resulting in increased agricultural waste and livestock manure production. Wheat straw and cow dung are rich nutrient sources and, if not utilized properly, may lead to environmental pollution. Keeping in view the cultivation of Agaricus bisporus on straw/manure-based substrate, the current study aimed to optimize the conventional manure preparation technique to reduce nutrient losses and keep the quality of manure at its best. The treatments were considered as traditional and optimized schemes for mushroom substrate preparation. The results achieved herein indicated that the nutrient losses were low in the optimum scheme. For carbon (C), the loss was 43.55% at the substrate stage in the traditional scheme and reduced to 37.75% in the optimum scheme. In the case of nitrogen (N), the loss was 22.01% in the traditional scheme and was lower (18.49%) in the optimum scheme. The nutrient concentration in Agaricus bisporus was higher with the optimum scheme compared with the traditional scheme. It was 1.74% for C, 7.17% for N, 3.58% for phosphorus (P), and 4.92% for potassium (K). The optimum scheme also improved the Agaricus bisporus yield per unit area (84.55%) and the total yield (28.92%). The net income of the optimum scheme was 102.95% higher compared to the traditional scheme. The economic analysis also revealed that the benefit–cost ratio of the optimum scheme was high (48.86%) compared with the traditional scheme. This study concludes that the use of the optimum scheme can better utilize the wheat straw and cow manure waste for substrate preparation and reducing nutrient losses. In addition, the final mushroom residue can also be used as a leftover substrate for further utilization.

Heteroepitaxial Growth of NiO Thin Films on (‐201) β‐Ga2O3 by Mist Chemical Vapor Deposition

The growth of NiO epitaxial thin films on (‐201) β‐Ga2O3 by mist chemical vapor deposition (CVD) and the effects of carrier gas selection (N2 and O2) and substrate preannealing treatment on the structural and morphological properties on the grown thin films are explored. X‐ray diffraction analysis reveals successful epitaxial growth with the orientation relationship (111) NiO [0‐11] || (‐201) β‐Ga2O3 [010]. As a carrier gas, O2 results in single‐domain NiO films while N2 leads to the formation of rotational domains. Atomic force microscopy and field‐emission scanning electron microscopy confirm the lateral growth of NiO films, thus highlighting the importance of substrate preannealing at 1200 °C in oxygen atmosphere to obtain flat, high‐quality films. The results demonstrate that the method of mist CVD combined with appropriate substrate preparation and carrier gas selection is effective for the growth of high‐quality NiO/β‐Ga2O3 heterostructures. This achievement opens new possibilities for the development of wide‐bandgap p–n heterojunctions, potentially advancing the field of high‐power oxide‐based electronic devices.

Oxidation Behaviour of TiC/TiN Coatings Deposited by Chemical Vapor Deposition: Mechanisms, Structures, and Properties

This review explores the oxidation behavior of titanium carbide (TiC) and titanium nitride (TiN) coatings deposited by chemical vapor deposition, with a focus ontheirindustrial applications as wear-resistant coatings for cuttingtools. It examines effect of process parameters—such as temperature, pressure, precursor composition, and substrate preparation—on formation and performance of TiC/TiN coatings. The review evaluates the microstructural characteristics of these coatings, including crystal structure, using X-ray diffraction analysis. Also, the review covers the mechanical properties, such as hardness, wear resistance, and adhesion strength. Additionally, the review covers the thermal stability of TiC/TiN coatings, emphasizing their ability to maintain structural integrity at high temperatures, which is essential for the performance of cutting tools and other industrial components. A major focus is the oxidation behavior of TiC/TiN coatings, including the impact of coating composition, deposition methods, and environmental conditions. The review details oxidation kinetics and mechanisms, revealing various stages of oxidation at different temperatures. It also examines oxide scale morphology and its effect on coating properties. Finally, this review reveals the importance of alloying elements, like silicon, in improving oxidation resistance. Composite coatings such as TiSiN and TiSiCN are shown to offer better high-temperature stability compared to traditional TiN coatings. The effects of coating thickness and the benefits of multilayer coatings for enhanced oxidation resistance are also discussed. Received: 14 February 2024 | Revised: 20 September 2024 | Accepted: 8 October 2024 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement Data sharing is not applicable to this article as no new data were created or analyzed in this study. Author Contribution Statement Osamah Ihsan Ali: Conceptualization, Methodology, Validation, Formal analysis, Investigation, Data curation, Writing - original draft, Writing - review & editing, Visualization, Supervision, Project administration, Funding acquisition. István Gábor Gyurika: Conceptualization, Funding acquisition.

Introduction and Development of Surface-Enhanced Raman Scattering (SERS) Substrates: A Review.

Since its discovery, the phenomenon of Surface Enhanced Raman Scattering (SERS) has gradually become an important tool for analyzing the composition and structure of substances. As a trace technique that can efficiently and nondestructively detect single molecules, the application of SERS has expanded from environmental and materials science to biomedical fields. In the past decade or so, the explosive development of nanotechnology and nanomaterials has further boosted the research of SERS technology, as nanomaterial-based SERS substrates have shown good signal enhancement properties. So far, it is widely recognized that the morphology, size, composition, and stacking mode of nanomaterials have a very great influence on the strength of the substrate SERS effect. Herein, an overview of methods for the preparation of surface-enhanced Raman scattering (SERS) substrates is provided. Specifically, this review describes a variety of common SERS substrate preparation methods and explores the potential and promise of these methods for applications in chemical analysis and biomedical fields. By detailing the influence of different nanomaterials (e.g., metallic nanoparticles, nanowires, and nanostars) and their structural features on the SERS effect, this article aims to provide a comprehensive understanding of SERS substrate preparation techniques.

Unleashing the Potential of Different Method of Paddy Straw Substrate Bag for Enhanced Yield and Biological Efficiency of Milky Mushroom

Mushrooms, particularly Calocybe indica, are highly regarded for their distinctive flavour and numerous health benefits. This study investigates various method of paddy straw substrate bags: rolled paddy straw, intact paddy straw, and chopped paddy straw to optimize the cultivation of C. indica. Employing a Completely Randomized Design (CRD), we analysed growth parameters, yield, and biological efficiency of mushrooms cultivated on these substrates. The results indicated that chopped paddy straw was the most effective substrate, significantly reducing the time for spawn run to 14.20 days, pinhead formation to 11.80 days, and sporophore maturation to 10.20 days. This method yielded the highest overall production at 664.50 g, along with a biological efficiency of 66.45%. In contrast, intact paddy straw exhibited moderate growth performance, while rolled paddy straw resulted in the lowest yield at 451.30 g and took the longest time for all growth stages, which may be attributed to less compactness in the substrate beds. The number of sporophores produced also varied, with chopped paddy straw yielding an average of 10.6 sporophores, compared to 8.6 from intact paddy straw and 7.2 from rolled paddy straw. Although stipe length and pileus diameter showed non-significant differences among treatments, they did not contribute meaningfully to yield or biological efficiency. Overall, the findings highlight that chopped paddy straw is the most suitable substrate preparation method for cultivating C. indica, enhancing both yield and efficiency in production. This research contributes valuable insights for mushroom cultivation practices, particularly in tropical regions where high temperatures prevail.

A critical review of the microcosm method in soil animal ecology

The microcosm method is widely used in research on soil animal ecology because it allows for controlled manipulations of fauna, climate, and soil properties. However, differences in biotic and abiotic conditions between the microcosm and the natural soil ecosystem it is intended to represent may bias the experimental results. On the basis of literature, potential influences of the following factors were discussed: (1) Microcosm volume and duration of the incubation period. (2) Preparation of the microcosm substrate, with emphasis on the choice between homogenised substrate and intact soil cores. (3) Incubation conditions (moisture, temperature and drainage). (4) Biotic diversity in the microcosm soil, with emphasis on (a) the general problem of low biodiversity in microcosms, (b) the unnatural situation in microcosms without plants, (c) differences in microflora composition between “faunal” and “non-faunal” treatments, and (d) relative densities of the organisms present. Possible ways of dealing with a few of these problems were also discussed.

An Effective and Controllable Platform with Ag-Stepped Nanocone Arrays Serving as Stable SERS Substrate

Facile, controllable and efficient SERS substrate preparation has always been the focus project in the SERS field, especially the solid-state nanoarray substrate. Herein, a simple and convenient method for preparing a series of homogeneous Ag-stepped nanocone arrays (Ag-SNCAs) using polymer nanocompression printing is presented. By analyzing the 1162[Formula: see text]cm[Formula: see text] characteristic peak of crystal violet (CV), the relative standard deviation (RSD) of the Raman intensity was only 4.71%. The detection limit of malachite green (MG) reached 0.001[Formula: see text]ppm, and it also has good SERS detection results for drug molecules such as melamine, methadone, morphine, methamphetamine and thiabendazole. This work provides a large area uniform and controllable preparation method of sharp cone nanostructure array, which has important application in plasmonic photocatalysis and deep light field regulations.

Assessment of concrete-to-concrete shear bond behavior using 3-D direct shear testing

The interfaces that develop when fresh concrete is poured onto existing substrates are noted for their vulnerability and influence on the durability and integrity of the composite structure. Studies on the shear bond properties and failure mechanisms of such composite concrete-to-concrete joints under normal stress are essential for developing predictive and numerical models that accommodate various levels of joint substrate roughness. This study aims to use an innovative 3D shearing box, BCR3D, to analyze the shear behavior of concrete-to-concrete joints under direct shear tests at a constant normal stress. The influence of the degree of surface roughness on the pure shear behavior of these joints was assessed at a normal stress level of 1 MPa. The substrate post-hardening surface morphology was evaluated using a high-resolution laser profilometer. Statistical surface roughness parameters were computed using MATLAB. A parametric study was carried out involving bond strength, residual shear stress, contractive-dilative behaviors, and total fracture energy. Results showed that bond strength, dilative normal displacement, and total fracture energy were proportional to the substrate surface roughness. Residual shear stress was not affected by the initial surface roughness. Dilative normal displacements were more significant for specimens with higher surface substrate roughness due to interlocking, with values reaching up to 1.77 mm. Joints with high substrate surface roughness exhibited similar bond strength and fracture energy to those obtained from the monolithic specimens, underscoring the significance of substrate preparation before casting new concrete layers.

A Comprehensive Review on Studying and Developing Guidelines to Standardize the Inspection of Properties and Production Methods for Mycelium-Bound Composites in Bio-Based Building Material Applications.

Mycelium-bound composites (MBCs) represent a promising advancement in bio-based building materials, offering sustainable alternatives for engineering and construction applications. This review provides a comprehensive overview of the current research landscape, production methodologies, and standardization ideas related to MBCs. A basic search on Scopus revealed over 250 publications on MBCs between 2020 and 2024, with more than 30% focusing on engineering and materials science. Key studies have investigated the physical and mechanical properties of MBCs, optimizing parameters such as substrate type, fungal species, incubation time, and post-processing to enhance material performance. Standardizing the inspection of MBC properties is crucial for ensuring quality and reliability. Various testing standards, including those from the American Society for Testing and Materials (ASTM), the International Organization for Standardization (ISO), the Japanese Industrial Standard (JIS), European Standards (EN), Deutsches Institut für Normung (DIN), and the Thai Industrial Standards Institute (TIS), are utilized to evaluate density, water absorption, compression strength, tensile strength, insulation, and other critical properties. This review highlights the distinction between lab-scale and apply-scale testing methodologies, emphasizing the need for comprehensive evaluation protocols. Additionally, the production process of MBCs involves critical steps like substrate preparation, fungal species selection, and mycelium growth, necessitating the implementation of good manufacturing practices (GMPs) to ensure consistency and quality. The internal and external structures of MBCs significantly influence their performance, necessitating standardized inspection methods using advanced techniques such as scanning electron microscopy (SEM), X-ray computed tomography (CT) scanning, and surface profilometry. By establishing robust inspection protocols and production standards, the industry can enhance the reliability and adoption of MBCs, contributing to innovations in materials science and promoting environmental sustainability. This review underscores the importance of interdisciplinary collaboration, advanced characterization tools, and regulatory frameworks to address challenges and advance the field of MBCs.

Synthesis of TiO2 Thin Film with Cobalt Doping Using Sol-Gel Spin-Coating Technique as a Solar Cell Material

Research has been done on thin films by mixing TiO2 with cobalt doping and adding HCI as a solar cell material. The aim of this research is to produce a thin layer that is good for use in solar cells. This research has several stages, namely: 1) weighing cobalt and titanium; 2) glass substrate preparation; 3) making a sol-gel solution; 4) thin layer deposition; and 5) heating the sample. From these several stages, the result was that a pure TiO2 solution without doping obtained a thick white solution, whereas the more doping used, the fainter the color of the solution obtained. The thin-layer synthesis process uses a spin-coating method assisted by a modified centrifuge to evenly distribute the sol-gel solution on the surface of the glass substrate

Preparation and characterization of peptide-modified core-shell fibrous substrates with UV-blocking properties for corneal regeneration applications

Effective UV protection is a key aspect of substrates directly exposed to UV radiation. Therefore, in the present study, fibrous substrates of core–shell morphology (PCL-core, PVP-shell) containing peptides based on tryptophan, tyrosine and cysteine (W6, YYC2 and YYC3) were prepared. Spectrophotometric studies showed UV absorption by peptides containing tyrosine and tryptophan in the UVB (up to 80%) and UVA (up to 40%) ranges. Cysteine, in turn, contributed to high antioxidant properties, confirmed by DPPH assay. The presence of peptides contributed to a nonwoven fabric characterized by the ability to absorb UV radiation and prevent the occurrence of oxidative stress (caused by the presence of free radicals). In turn, the increase in the surface zeta potential of the nonwoven after UV irradiation and higher thermal stability (demonstrated by DSC studies) indicated the crosslinking of the PVP layer under UVR, which further contributes to the increased protection of the nonwoven against its effects. In summary, obtained nonwoven exhibited functional similarity to the native cornea, providing a potential solution for enhancing corneal tissue engineering and regenerative medicine applications.