Search

This study intends to improve the dielectric properties of PMMA/PEG/SiO2/SiC nanostructures for use in flexible pressure sensors and electrical nanodevices. PMMA/PEG films and PMMA/PEG films doped with SiO2 and SiC NPs were created using a casting technique. The structural properties of PMMA/PEG/SiO2/SiC nanostructures were examined using FTIR and an optical microscope. The dielectric properties were assessed using an LCR meter across a frequency range from 100 Hz to 5 MHz. The analysis of the structural features of PMMA/PEG/SiO2/SiC nanostructures showed a significant presence of SiO2 and SiC nanoparticles in the PMMA/PEG material and strong integration between SiO2 and SiC nanoparticles and the PMMA/PEG matrix. The dielectric properties showed an increase in the dielectric parameters of PMMA/PEG as the concentration of SiO2-SiC NPs increased. The dielectric constant and AC electrical conductivity of PMMA/PEG rose by approximately 39% and 49%, respectively, with low dielectric loss values ranging from 0.14 to 0.275 at 100 Hz. These findings suggest that PMMA/PEG/SiO2/SiC nanostructures may be suitable for a variety of nanoelectronics applications. The dielectric properties of PMMA/PEG/SiO2/SiC nanostructures changed as the frequency increased. The structure and dielectric properties of the PMMA/PEG/SiO2/SiC nanostructures suggest they can be used in a variety of flexible nanoelectronics applications due to their low-cost, high-energy storage capability, and minimal energy loss. An investigation was conducted on the pressure sensor application of PMMA/PEG/SiO2/SiC nanostructures. The results indicated that the PMMA/PEG/SiO2/SiC nanostructures exhibit high sensitivity to pressure, exceptional flexibility, and strong environmental resilience in comparison to other sensors. [ABSTRACT FROM AUTHOR]

Tryptophan (Trp) is an essential amino acid required by the body. It can only be consumed through daily food intake. Accurate determination of Trp in food and biological samples was crucial for safeguarding human health. Fluorescence analytical technique is one of the most promising methods for sensing Trp because of its high selectivity, good sensitivity and fast response-time. Most current reviews lack a summary of the detection of nutrients such as Trp. A review of Trp-responsive fluorescent sensors for food, pharmaceutical and biological samples (2017 onwards) was presented in this paper. The fluorescence mechanism, sensor types and practical applications of these sensors were discussed, and challenges and future perspective to the development of Trp-responsive fluorescent sensors were presented. [ABSTRACT FROM AUTHOR]

As a new type of artificial enzyme, a nanozyme is an ideal substitute for natural enzymes and has been successfully applied in many fields. However, in the application of biomolecular detection, most nanozymes have the disadvantages of long reaction times or high detection limits, prompting researchers to search for new efficient nanozymes. In this work, the enzyme-like activities of three polyoxometalate-based iron-organic complexes ([Fe(bpp)2](Mo6O19), [Fe(bpp)2]2(Mo8O26)·2CH3OH, and [Fe(bpp)2]4H[Na(Mo8O26)]3), namely, FeMo6, Fe2Mo8, and Fe4Mo8Na, were analyzed. All three polyoxometalate-based iron-organic complexes were found to be capable of catalyzing hydrogen peroxide (H2O2) to oxidize 3,3′,5,5′-tetramethylbenzidine and o-phenylenediamine, resulting in visible color changes, further exhibiting peroxidase-like activity. Results showed that Fe4Mo8Na had more active sites due to its long chain structure, endowing more prominent peroxidase-like activity compared with Fe2Mo8 and FeMo6. A colorimetric sensing platform for H2O2 and ascorbic acid detection based on Fe4Mo8Na was established. The linear response range for H2O2 detection was 0.5–100 μM, and the detection limit was 0.143 μM. The linear response for ascorbic acid detection ranges from 0 to 750 μM with a detection limit of 1.07 μM. This study provides a new perspective for developing new nanozymes and expanding the sensing and detection application of nanozymes. [ABSTRACT FROM AUTHOR]

This study explores the synthesis of La 10 Si 6 O 27 :Sm3+ nanoparticles (LSNP) with varying samarium (Sm3+) concentrations (0–8 mol%) using eco-friendly solution combustion method with urea as a fuel. Using powder X-ray diffraction (PXRD), we determined that the nanoparticles typically measure between 15 and 17 nm and display a spherical morphology. These rare earth (RE)-doped nanoparticles were employed as a novel photocatalyst for the degradation of malachite green (MG) dye, exhibit unprecedented photocatalytic efficiency. The release of OH radicals during the degradation process was found to vary with the chemical structure and concentration of the photocatalyst, with the 6 mol% LSNP formulation showing a significant advancement under both UV and sunlight. Electrochemical assessments revealed that these nanoparticles exhibit excellent cyclic stability and robust performance. Notably, the specific capacitance of the nanoparticles increased with the samarium concentration, reaching a peak of 261.3 F/g in 0.1 M HCl. Furthermore, graphite-modified electrodes incorporating these nanoparticles showed significant potential as sensitive materials for detecting mercury and lead in concentrations as low as 1–6 mM, underscoring the versatility and functional adaptability of the synthesized nanoparticles in environmental and electrochemical applications. The prepared La 10 Si 6 O 27 :Sm3+ nanoparticles The nanoparticles demonstrated an optimal photocatalytic efficiency of 95.5 % under UV light and 88.15 % under sunlight at 6 mol% Sm3+ doping. Additionally, a peak specific capacitance of 261.3 F/g was achieved in 0.1 M HCl. [ABSTRACT FROM AUTHOR]

This study reveals one-step green synthesis of plant inspired silver nanoparticles (Ag-NPs). The synthesis procedure relies on the bio-reduction of Ag+ to Ag0 using orange waste (orange peel) extract as cheap, readily available, sustainable, biocompatible feedstocks as a reducing and stabilizing agent. The prepared Ag-NPs passed through a full characterization procedure for better confirmation and elucidation of optical and structural properties. The fluorescence of the prepared Ag-NPs has a quantum yield of 17.15% enabling its potential use in chemical sensing of drugs. Ag-NPs are conceived to be used as a fluorescent nano sensor for sensitive, ecofriendly, rapid spectrofluorimetric determination of two recent direct oral anticoagulants, namely, rivaroxaban (RIV) and edoxaban tosylate monohydrate (EDT); COVID-19 adjunctive drugs in their raw materials and pharmaceutical tablets. The fluorescence of the prepared Ag-NPs at 333 nm (λ ex = 258 nm) was found to be substantially quenched in existence of increasing concentrations of each drug. The quenching mechanisms were studied and explained. The validation of the method revealed linear correlation over the ranges of 0.5–10 µg/ml with an excellent regression correlation (r = 0.9999) for both drugs with minimum detection limits of 0.14 and 0.16 µg/ml for rivaroxaban and edoxaban tosylate monohydrate, correspondingly. Three different metrics were employed for verifying the greenness profile of the presented study. The findings of the greenness assessment were congruent and compatible with the green synthesis procedure, ecofriendly analysis, and the exclusion of using organic solvents and noxious materials opening an avenue for green synthesis of nanoparticles instead of chemical and physical methods. [ABSTRACT FROM AUTHOR]

N-butanol, a volatile organic compound prevalent in numerous industrial processes, poses significant risks to human health and the environment if not properly monitored. Consequently, the development of high-sensitivity n-butanol sensors is imperative. For this reason, NdFeO 3 nanoparticles were successfully synthesized by hydrothermal method and used for the detection of n-butanol. They were fully analyzed using characterization techniques such as XRD, BET, EDX, SEM, TEM and XPS. The test results revealed that the prepared samples exhibited a granular structure with an average diameter of approximately 65 nm. The specific surface area measured 15.415 m2/g, and the pore size was determined to be 16.638 nm. The NdFeO 3 sensor responds up to 441 for 100 ppm n-butanol at 260 °C, response and recovery times were 33 s and 7 s respectively. The response value of the NdFeO 3 sensor is still 4.3 for 1 ppm n-butanol with a minimum detection limit of 0.024 ppm. Simultaneously, the NdFeO 3 sensor has excellent selectivity, stability and moisture resistance. These good sensing properties indicate that this work provides a possible strategy for developing an economical and repeatable high performance gas sensor for the detection of n-butanol. [ABSTRACT FROM AUTHOR]

Artemesia tridentata is a foundational plant taxon in western North America and an important medicinal plant threatened by climate change. Low-cost fabrication of sensors is critical for developing large-area sensor networks for understanding and monitoring a range of environmental conditions. However, the availability of materials and manufacturing processes is still in the early stages, limiting the capacity to develop cost-effective sensors at a large scale. In this study, we demonstrate the fabrication of low-cost flexible sensors using laser-induced graphene (LIG); a graphitic material synthesized using a 450-nm wavelength bench top laser patterned onto polyimide substrates. We demonstrate the effect of the intensity and focus of the incident beam on the morphology and electrical properties of the synthesized material. Raman analyses of the synthesized LIG show a defect-rich graphene with a crystallite size in the tens of nanometers. This shows that the high level of disorder within the LIG structure, along with the porous nature of the material provide a good surface for gas adsorption. The initial characterization of the material has shown an analyte response represented by a change in resistance of up to 5% in the presence of volatile organic compounds (VOCs) that are emitted and detected by Artemisia species. Bend testing up to 100 cycles provides evidence that these sensors will remain resilient when deployed across the landscapes to assess VOC signaling in plant communities. The versatile low-cost laser writing technique highlights the promise of low-cost and scalable fabrication of LIG sensors for gas sensor monitoring. [ABSTRACT FROM AUTHOR]

Over the past few years, the elimination of pharmaceuticals from polluted water has been a major challenge for many researchers. The presented project reports the photoelectrochemical (PEC) detection of ciprofloxacin (CIP) by using a BiVO 4 thin layer prepared by a facile spin coat method on an Indium doped tin oxide (ITO) glass as photoanode. The mesoporous nanostructure of the fabricated photoanodes was characterized with UV–vis diffusion transmission spectra, Tauc plot, electrochemical impedance spectroscopy, Mott-Schottky diagram, and chronoamperometry analysis. After optimizing some of the key factors affecting current response of the photoanode, the PEC detection results showed that the BiVO 4 thin-layer photoanode had high and stable photocurrent responses for CIP under UV-Vis light irradiation. Furthermore, the fabricated PEC sensor displayed two wide-spreading linear detection ranges from 0.05 to 100 nM and 100–5700 nM with very low detection limits (LOD) of 0.016 nM. Furthermore, the interferences evaluation demonstrated excellent selectivity of the PEC sensor toward CIP molecules in the presence of other interfering species in solution. Therefore, the marked performance of this photoelectrode in the PEC detection of CIP, extraordinary stability, and admirable reproducibility suggests its potential as a photoanode for the pharmaceutical pollutant oxidation including various antibiotics in wastewater. • Synthesized BiVO 4 material exhibited excellent PEC activity. • ITO/BiVO 4 was successfully applied for the PEC sensing of CIP residues. • This PEC sensor presented excellent performance than another PEC sensor. • The application of sensor was studied in athlete's biological samples. [ABSTRACT FROM AUTHOR]

In this paper, Charge Plasma Nanowire Tunnel Field Effect Transistor based sensor is proposed for the recognition of Oxygen (O2) gas molecules by means of a Silicon Germanium (Si1-xGex) sourced device abbreviated as SiGe-CP-NW-TFET. The electrical performances of SiGe-CP-NW-TFET have been compared with the conventional Charge Plasma Nanowire Tunnel Field Effect Transistor (CP-NW-TFET). The parameters measured for comparison are ION, IOFF, ION/IOFF, Subthreshold slope (SS), and threshold voltage (Vt). The proposed SiGe-CP-NW-TFET has better electrical performance as compared to Si-CP-NW-TFET. Further, the device characteristics such as electric potential, electric field, charge carriers, and energy band diagram of both the devices have also been compared. The fundamental physics of the proposed sensor is also explored from a comprehensive electrostatic study of the tunnelling junction in the context of gas molecule adsorption. The influence of device constraints of the proposed SiGe-CP-NW-TFET on the electrical performance indicators has also been studied. The device parameters e.g. oxide thickness, extended gate length, silicon film thickness, and molar concentration of SiGe at the source side are considered. The impact of oxide thickness, extended gate length, the radius of NW, and the concentration of SiGe (molar) at the source side have been analysed on the sensitivity of the O2 gas sensor. The presented Oxygen gas sensor has an ION/IOFF ratio of 3.65 × 107 and a subthreshold slope of 58.23 mV/decade. [ABSTRACT FROM AUTHOR]

A biological reduction method for silver nanoparticles was employed using Cassia alata extract from plant leaves, which functions as a reducing agent and the metallo‐surfactant [Co(dqn)2(C12H27N)2]3+ (dqn = dipyrido[3,2‐f:2′,3′‐h]‐quinoxaline; C12H27N)2 = dodecylamine) acting as both stabilizing and capping agent. The ratio of Ag nanoparticles (AgNPs) formation was adjusted to be equal to the amount of AgNO3, along with variations in the amount of plant leaf extract, the metallo‐surfactant, pH, surrounding temperature, and the length of interaction periods. High‐resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FE‐SEM), energy‐dispersive spectroscopy (EDS), and energy‐dispersive X‐ray analysis (EDAX) were used to confirm the formation of AgNPs. The infrared results indicate the presence of hydroxyl, amine, and carboxylate groups in the extract plays a crucial role in the reduction process. Additionally, the metallo‐surfactant acts as a capping agent for the silver nanoparticles, preventing agglomeration. By adjusting the acidity of the solution and the quantity of the additive metallo‐surface active agent utilized, the size of AgNPs can be precisely regulated. The relativistic effects observed in this metallo‐surfactant‐assisted silver nanoparticle demonstrate excellent reduction capabilities for nitro compounds, effective dye degradation, and mercury sensing applications. [ABSTRACT FROM AUTHOR]

This study presents the electrochemical reduction of graphene oxide (GO) to reduced graphene oxide (rGO) directly onto flexible interdigitated gold electrodes and its application as a strain sensor. GO reduction is achieved using cyclic voltammetry (CV). Remarkably, only a single CV cycle transformed GO into rGO to obtain low‐resistance (≈100 Ω) devices. The reduction of GO is confirmed using Raman spectroscopy and electrical measurements. rGO on flexible interdigitated gold electrodes exhibits graphene‐like characteristics when used as electrolyte‐gated field‐effect transistors. The fabricated devices display a gauge factor (GF) of ≈3.7 in the 0–794 με range. This value represents a substantial improvement, ≈60% higher than traditional metallic strain sensors, which have a GF of ≈2.1. Most importantly, the rGO strain sensor exhibits fast response (1.1 s) and recovery (0.92 s) times. The rGO sensor is mounted on a clamp with an adjustable diameter, which reveals exceptional flexibility and bendability without damage or degradation. These results highlight the potential of rGO for advancing strain‐sensing applications, offering promising opportunities for the future of this technology. [ABSTRACT FROM AUTHOR]

Fluorescence sensors for complicated molecules such as pesticides were paid much attention lately due to the merits of simple operation, high sensitivity and selectivity, and in‐situ detection. In this work, a novel fluorescent sensor for pesticide starane was prepared based on imidazolium‐decorated bis‐cyanostilbene macrocycle (IBM). IBM exhibited the obvious "turn‐on" fluorescence change from dark blue‐green to bright blue after sensing starane with the high sensing selectivity among 28 kinds of guests. The detecting limitation was as low as 0.011 μM, which was the lowest one in literatures. The sensing mechanism was confirmed as that starane was located in cavity of IBM based on the molecular interaction of multiple hydrogen bonds, π‐π stacking and hydrophobic interaction. The application experiments suggested that starane was examined well on test paper with good selectivity and was quantitatively detected in water samples, implying the good real‐time and in‐situ application potential for IBM on sensing starane in real environment and daily life. [ABSTRACT FROM AUTHOR]

Calixarenes, which can be functionalized in a wide range of derivatives, are one of the chemicals that should be considered for safe energy storage. This research focused on utilization Density Functional Theory (DFT) method to investigate the hydrogen sensing and adsorption characteristics of two distinct calix[4]arene compounds and their corresponding metal complexes. In the study, electronic sensor properties were investigated by using different approaches. In addition, the dynamic stability was determined by Molecular dynamics (MD) calculations. Perturbation theory analysis has revealed the importance of the relationship between Fe and S atoms. The adsorption energy on the C1 structure with the best adsorption ability was calculated as −10.3 kJ/mol. According to RDG analysis, weak van der Waals interactions play a role in adsorption. The C2‐Fe complex with a substantial decrease in the HOMO–LUMO gap has been identified and explained as an applicant material for electronic sensor against hydrogen molecule. Moreover, it was also determined that the C2‐Fe complex has work function type gas sensor property against hydrogen molecule. According to the results, metal‐calixarene complexes can play an important role in hydrogen safety in the future. [ABSTRACT FROM AUTHOR]

Room temperature detection is a crucial objective in semiconductor sensor research, given its inherent benefits including reduced energy consumption, extended sensor lifespan, and significant reduction of safety hazards. Herein, novel room temperature sensing materials, SnO 2 -modified In 2 O 3 porous microrods were synthesized, which exhibited exceptional sensing capability towards formaldehyde at room temperature. Specifically, the 5%-SnO 2 /In 2 O 3 porous microrods demonstrate an impressive sensing response across varying formaldehyde concentrations, even at sub-ppm levels (0.1 ppm, 5.22), with a theoretical detection limit of 5.47 ppb, thereby enabling the detection of trace amounts of formaldehyde. Moreover, the sensors exhibit superior formaldehyde selectivity, rapid response characteristic, as well as good stability and reproducibility. The exceptional formaldehyde sensing ability of the SnO 2 /In 2 O 3 sensor primarily arises from the creation of n-n heterojunctions at the SnO 2 /In 2 O 3 interface, effectively modulating the interfacial potential. Additionally, the presence of SnO 2 enhances the amount of surface-adsorbed oxygen species and active sites, thereby boosting sensing response. The porous rod-like structures further facilitate gas adsorption and diffusion, enhancing gas sensing capabilities. This work presents a novel strategy for constructing SnO 2 -In 2 O 3 heterojunctions to achieve room-temperature formaldehyde detection. [ABSTRACT FROM AUTHOR]

The presence of lead(II) ion poses a significant threat to water systems due to their toxicity and potential health hazards. The detection of Pb2+ ions in contaminated water is very crucial. The ionic liquid functionalized multiwalled carbon nanotubes (IL@MWCNT) nanocomposite was fabricated using ionic liquid (IL) 1‐methyl‐3‐(4‐sulfobutyl)‐imidazolium chloride and multiwalled carbon nanotubes (MWCNTs) for detection of lead(II) ions. It is a novel method to heterogenize the layer of IL on the surface of MWCNTs. The XPS and FTIR analyses confirm that the ionic liquid is not decomposed during annealing process. Moreover, the XRD analysis shows the presence of MWCNTs and carbon quantum dots (CQDs). The HRTEM results exhibit the aggregation of MWCNTs with IL, and formation of small distorted round shaped flakes of CQDs. Further, the successful heterogenization of IL on the surface of MWCNTs is also confirmed by TGA‐DSC analysis. The quenching phenomenon of nanocomposite was observed by UV‐Visible spectroscopy. The nanocomposite exhibits high performance for the selective detection of lead(II) ions in comparison to other metal ions. The presence of lead(II) ions eventually reduced the intensity of absorption. A limit of detection (LOD) of 9.16 nM was attained for Pb2+ ions in a concentration range of 0–20 nM. [ABSTRACT FROM AUTHOR]

Methidathion (MTDT), a common organophosphorus pesticide with high insecticidal activity, is widely used for pest control. However, the misuse of MTDT leads to widespread residues and endangers human health. Therefore, it is crucial to develop a simple and highly sensitive method for the detection of MTDT residues. Herein, ZIF-90/MnO2/g-C3N4/Fe3O4 composite particles were synthesized: The MnO2 nanosheets could absorb the energy of the excited g-C3N4 to quench the ECL of g-C3N4 while ZIF-90 acted as a mimetic enzyme to catalyze the formation of thiocholine from MTDT. The thiocholine caused the reduction of MnO2 to Mn2+, restoring the ECL signal of g-C3N4. Combined with molecular imprinting technique, an electrochemiluminescence sensor was constructed for the determination of MTDT. The determination range was 1.00 × 10–9 ~ 7.00 × 10–7 g/L, and the detection limit was 6.58 × 10–10 g/L. Structurally similar organophosphorus pesticides showed no cross-reactivity. The method has high sensitivity and specificity, and has been successfully applied to the determination of MTDT residue in fruits with recoveries in the range 93.75% ~ 102.37%. [ABSTRACT FROM AUTHOR]

Early detection of ovarian cancer (OC) is crucial for effective management and treatment, as well as reducing mortality rates. However, the current diagnostic methods for OC are time-consuming and have low accuracy. Surface plasmon resonance (SPR) biosensors offer a promising alternative to conventional techniques, as they enable rapid and less invasive screening of various circulating indicators. These biosensors are widely used for biomolecular interaction analysis and detecting tumor markers, and they are currently being investigated as a rapid diagnostic tool for early-stage cancer detection. Our main focus is on the fundamental concepts and performance characteristics of SPR biosensors. We also discuss the latest advancements in SPR biosensors that enhance their sensitivity and enable high-throughput quantification of OC biomarkers, including CA125, HE4, CEA, and CA19-9. Finally, we address the future challenges that need to be overcome to advance SPR biosensors from research to clinical applications. The ultimate goal is to facilitate the translation of SPR biosensors into routine clinical practice for the early detection and management of OC. [ABSTRACT FROM AUTHOR]

The preparation of a hybrid nanomaterial is reported by covalently attaching 3,5-dinitrobenzoic acid groups to the surface of oxidized multi-walled carbon nanotubes using 1,6-diaminohexane as cross-linking agent. This nanomaterial, modified with the redox mediator, was used as transduction element to construct an amperometric sensor for the efficient indirect determination of glutathione reductase at a low working potential of − 0.05 V, through the oxidation of unconsumed nicotinamide adenine dinucleotide phosphate (NADPH) in the enzymatic reaction. The sensor exhibited an excellent linear response in the range 1.6 to 174 µU/µL, with high reproducibility and selectivity. The developed device was successfully validated in real samples, accurately determining the active enzyme in diluted human serum, making it a promising alternative for the determination of glutathione reductase and other related NADPH-dependent enzymes with relevance in clinical analysis. [ABSTRACT FROM AUTHOR]

In yeast, control of sulfur amino acid metabolism relies upon Met4 , a transcription factor that activates the expression of a network of enzymes responsible for the biosynthesis of cysteine and methionine. In times of sulfur abundance, the activity of Met4 is repressed via ubiquitination by the SCF Met30 E3 ubiquitin ligase, but the mechanism by which the F-box protein Met30 senses sulfur status to tune its E3 ligase activity remains unresolved. Herein, we show that Met30 responds to flux through the trans-sulfuration pathway to regulate the MET gene transcriptional program. In particular, Met30 is responsive to the biological gas hydrogen sulfide, which is sufficient to induce ubiquitination of Met4 in vivo. Additionally, we identify important cysteine residues in Met30 's WD-40 repeat region that sense the availability of sulfur in the cell. Our findings reveal how SCF Met30 dynamically senses the flow of sulfur metabolites through the trans-sulfuration pathway to regulate the synthesis of these special amino acids. [ABSTRACT FROM AUTHOR]

Sensor technologies were integrated into a commercial sensor-guided hoeing system to counteract the force of gravity and reduce crop damage caused by the offset of hoeing in maize fields on sloping terrains. For this study, a hoe was equipped with a contact disc, sensors, an electric cylinder, and a decision support system. The offset of the hoe could be compensated in real time based on the automatic adjustment angle of the support wheel. In maize, three field experiments were conducted over two years to evaluate the system on three different slope gradients (between 4 and 12°). Plant populations were measured in each plot one day before and during hoeing to evaluate crop damage. However, for support wheel angle, Slope Compensation Intensity (SCI) 2 and 3, there were no significant crop plant losses in any trials. As a result, there was no hoe drifting during the sensor-based guidance along the rows. It has been verified that the development presented is functional and can counteract the force of gravity on slopes. This development aims to optimise the use of precision mechanical weed control and support farmers during hoeing on hilly terrain. • Tractor and machine are pushed down the slope by downhill force. • The hoe is not parallel to the tractor and plant losses will occur. • The offset of a hoe can be compensated by the developed slope-compensation system. • Crop losses can be compensated on hilly fields. [ABSTRACT FROM AUTHOR]

Background: Motion Tape (MT) is a low-profile, disposable, self-adhesive wearable sensor that measures skin strain. Preliminary studies have validated MT for measuring lower back movement. However, further analysis is needed to determine if MT can be used to measure lower back muscle engagement. The purpose of this study was to measure differences in MT strain between conditions in which the lower back muscles were relaxed versus maximally activated. Methods: Ten participants without low back pain were tested. A matrix of six MTs was placed on the lower back, and strain data were captured under a series of conditions. The first condition was a baseline trial, in which participants lay prone and the muscles of the lower back were relaxed. The subsequent trials were maximum voluntary isometric contractions (MVICs), in which participants did not move, but resisted the examiner force in extension or rotational directions to maximally engage their lower back muscles. The mean MT strain was calculated for each condition. A repeated measures ANOVA was conducted to analyze the effects of conditions (baseline, extension, right rotation, and left rotation) and MT position (1–6) on the MT strain. Post hoc analyses were conducted for significant effects from the overall analysis. Results: The results of the ANOVA revealed a significant main effect of condition (p < 0.001) and a significant interaction effect of sensor and condition (p = 0.01). There were significant differences in MT strain between the baseline condition and the extension and rotation MVIC conditions, respectively, for sensors 4, 5, and 6 (p = 0.01–0.04). The largest differences in MT strain were observed between baseline and rotation conditions for sensors 4, 5, and 6. Conclusions: MT can capture maximal lower back muscle engagement while the trunk remains in a stationary position. Lower sensors are better able to capture muscle engagement than upper sensors. Furthermore, MT captured muscle engagement during rotation conditions better than during extension. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) semiconductor components have excellent physical attributes, such as excellent mechanical ductility, high mobility, low dielectric constant, and tunable bandgap, which have attracted much attention to the fields of flexible devices, optoelectronic conversion, and microelectronic devices. Additionally, one-dimensional (1D) semiconductor materials with unique physical attributes, such as high surface area and mechanical potency, show great potential in many applications. However, isolated 1D and 2D materials often do not meet the demand for multifunctionality. Therefore, more functionality is achieved by reconstructing new composite structures from 1D and 2D materials, and according to the current study, it has been demonstrated that hybrid dimensional integration yields a significant enhancement in performance and functionality, which is widely promising in the field of constructing novel electronic and optoelectronic nanodevices. In this review, we first briefly introduce the preparation methods of 1D materials, 2D materials, and 1D/2D heterostructures, as well as their advantages and limitations. The applications of 1D/2D heterostructures in photodetectors, gas sensors, pressure and strain sensors, as well as photoelectrical synapses and biosensors are then discussed, along with the opportunities and challenges of their current applications. Finally, the outlook of the emerging field of 1D/2D heterojunction structures is given. [ABSTRACT FROM AUTHOR]

This study investigates the development of electrically conductive panels for application as emergency detection sensors in smart house systems. These panels, composed of wood chips coated with polymeric methylene diphenyl isocyanate, were modified with carbon black and carbon fibers to enable detection of moisture, temperature, and pressure variations. Manufactured via hot pressing, the panels retained standard mechanical properties and exhibited stable performance under diverse environmental conditions. Carbon black-filled panels achieved electrical percolation at a lower filler concentration (5%) compared to carbon fiber-filled panels. The incorporation of carbon black reduced the electrical resistivity to 8.6 ohm·cm, while the addition of carbon fibers further decreased it to 7.7 ohm·cm. In terms of sensor capabilities, panels containing carbon fibers demonstrated superior sensitivity to moisture and pressure changes. However, carbon black was ineffective for temperature sensing. Among the carbon fiber-filled panels, those with 20 wt.% concentration exhibited the best performance for moisture and pressure detection, whereas panels with 40 wt.% carbon fiber content displayed the most reliable and consistent temperature-sensing properties. [ABSTRACT FROM AUTHOR]

High-efficiency microcalorimeter arrays are required as imaging spectroscopy for X-ray microscopy in general and for astrophysics. We have developed in-house an array of Transition Edge Sensor (TES) X-ray microcalorimeters with mushroom-type absorbers which have a large area of 260 μ m square with multiple support stems. Insufficient thermal conductivity may degrade the energy resolution. We construct a 3D FEM simulation with thermal conduction and electric feedback circuit of TES. Estimated physical parameters were incorporated into the simulation to reproduce the measured pulse waveforms. As a result, the effect of the large absorber on the degradation of energy resolution was small for the mushroom-type absorber TES calorimeter. [ABSTRACT FROM AUTHOR]

The molten‐salt synthesis and electrochemical capacitive behaviors of porous carbon are reported using anthracite as the precursor. Upon synthesis, the binary KCl/K2CO3 molten salt not only exfoliates bulky anthracite to carbon nanosheets but also creates rich micro‐ and mesopores in the structure. The resulting porous carbon shows a large surface area of 1399.7 m2 g−1 and a total pore volume of 1.50 cm3 g−1. In 6.0 mol L−1 KOH aqueous electrolyte, it delivers a high specific capacitance of 245.6 F g−1 at a current density of 0.5 A g−1. Flexible micro‐supercapacitors with this porous carbon are assembled following an interdigitated design. The micro‐supercapacitor affords an area capacitance of 18.0 mF cm−2 and an energy density of 1.58 µWh cm−2 at a power density of 20 µW cm−2, and sustains 89.6% of the capacitance after 2000 cycles. Furthermore, the strain sensor fabricated by replacing the current‐collecting fluid at both ends of the electrode provides consistent and stable signal output, regardless of the degree of bending and the number of cycles. This study demonstrates the great potential of anthracite‐based porous carbon in flexible energy and electronic microdevices. [ABSTRACT FROM AUTHOR]

In this study, the extract obtained from the flowers of the Anchusa azurea (AA) plant was mixed with silver nitrate to obtain silver nanoparticles. The ion sensing ability of the obtained bio-sourced silver nanoparticles in aqueous solutions was investigated and the presence of Hg2+ ions was determined colorimetrically. Silver nanoparticles (AgNPs) prepared on Green Chemistry method, which is both an environmentally friendly and cost-effective synthesis technique, were characterised using different analytical tools. The mean particle size of AA-AgNPs from transmission electron microscopy (TEM) images was determined to be 22 nm in diameter. XRD measurements showed that the crystallite sizes of the synthesised AgNPs were in the face-centred cubic crystal structure with an average size of 22 nm, which is consistent with TEM results. AA-AgNPs showed absorption at 435 nm, indicating that AgNPs exhibit a strong surface plasmon resonance (SPR) and play a role in stabilisation. AgNPs synthesised with Anchusa azurea flowers were observed using UV-vis spectroscopy to selectively and sensitively detect mercury ions (Hg2+). When Hg2+ in aqueous solution was added to the AgNPs, the overall absorbance dramatically decreased and the colour changed from yellow to colourless. This study shows that AA-AgNPs can be used as a cost-effective material in optical sensors for colorimetric determinations. [ABSTRACT FROM AUTHOR]

There are many difficulties in growing tomatoes, such as erratic weather patterns, variable yields, and short shelf lives. Tomatoes are a staple food that is grown all throughout the world, particularly in climate-friendly areas such as Morocco. These areas are not free from the difficulties that present major obstacles for farmers, though. Modern agricultural techniques are increasingly using cutting-edge technologies, such as Internet of Things (IoT)-enabled smart greenhouses, to address these problems. In order to improve tomato output, this study presents an enhanced smart greenhouse model that incorporates the zoning principle. The method provides optimal plant growth and resource efficiency by separating the greenhouse into various zones, each tailored for specific growth stages and environmental circumstances. Precision farming and sustainable practices are made possible by the suggested systems real-time monitoring and control, which integrates sensors, actuators, and data analytics. The automatic irrigation system of the intelligent greenhouse prototype is additionally set up to offer the best possible support for the growth of tomato plants. The functionality and efficacy of the prototype are investigated through extensive laboratory testing and experimentation, providing insight into its potential influence on agricultural practices and practical practicality. The greenhouse that has been created with the help of IoT capabilities and the zoning concept has proven to be an effective instrument in assisting farmers in their attempts to grow tomatoes in an efficient and sustainable manner. Our comprehensive testing yielded data that demonstrate the zoning principle-integrated IoT-enabled smart greenhouse greatly improves tomato quality and production. This system demonstrates the benefits and practical applicability of sophisticated data-driven automation in agriculture by providing a scalable and sustainable solution to the problems encountered by tomato producers. [ABSTRACT FROM AUTHOR]

eHealth includes services and systems of healthcare and information technologies. A patient monitoring system is essential to have a medical professional be aware of the patient's condition. On the other hand, telecare medical information system (TMIS) makes a doctor able to make diagnoses and provide treatment advice to a patient via the Internet. How to ensure convenience and user privacy for eHealth at the same time is always an urgent issue. Because sensor networks make obtaining instantaneous information feasible, we first analyze related protocols and makes further discussions with proper modifications to ensure the patient monitoring system's security. Then we propose a biometrics-based mutual authentication scheme to ensure privacy and security for TMIS. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nonlinear acoustic signals, specifically the parametric effect, offer significant advantages over linear signals because the low frequencies generated in the medium due to the intermodulation of the emitted frequencies are highly directional and can propagate over long distances. Due to these characteristics, a detailed analysis of these signals is necessary to accurately estimate the Time of Arrival (ToA) and amplitude parameters. This is crucial for various communication applications, such as sonar and underwater location systems. The research addresses a notable gap in the literature regarding comparative methods for analyzing nonlinear acoustic signals, particularly focusing on ToA estimation and amplitude parameterization. Two types of nonlinear modulations are examined: parametric Frequency-Shift Keying (FSK) and parametric sine-sweep modulation, which correspond to narrowband and broadband signals, respectively. The first study evaluates three ToA estimation methods—threshold, power variation (Pvar), and cross-correlation methods for the modulations in question. Following ToA estimation, the amplitude of the received signals is analyzed using acoustic signal processing techniques such as time-domain, frequency-domain, and cross-correlation methods. The practical application is validated through controlled laboratory experiments, which confirm the robustness and effectiveness of the existing methods proposed under study for nonlinear (parametric) acoustic signals. [ABSTRACT FROM AUTHOR]

In the backdrop of the escalating incidents of mobile device theft and associated security challenges, a resilient and innovative solution is imperative. The traditional security mechanisms, largely reliant on the International Mobile Equipment Identity (IMEI), have been fraught with vulnerabilities, leading to a surge in incidents of device theft and data breaches. Addressing this pressing issue, we present a novel, two-tiered approach integrating sensor technology and blockchain to bolster mobile device security. This work aims to create and assess a dual-layered security strategy that uses blockchain and sensor technologies in a complementary way. Based on a rigorous conceptual framework, it explores a two-tiered security model that intricately combines sensor and blockchain technologies. This collaborative integration aims to provide an effective solution to the widespread challenges of theft and security breaches in mobile devices. The methodology employs a sensor layer for real-time data collection and processing to detect potential thefts, and activating alerts. The blockchain layer, invoked upon these alerts, initiates secure, transparent, and decentralized transactions for verification and validation across network nodes. This dual mechanism ensures swift and secure anti-theft actions, supported by an enhanced encryption standard. Our result analysis reveals the proposed system's superiority in computational time, energy consumption, and overall security levels when compared to existing protocols. The integration of real-time processing and blockchain's immutable nature promises reduced false positives and enhanced data integrity. The findings indicate that this integrative approach not only mitigates theft but also ensures data security, marking a significant stride in mobile security technology. In conclusion, this two-layered system promises a scalable, efficient, and robust solution to mobile device theft and data breaches, with potential impacts transcending individual device security to influence broader data privacy and security paradigms, thus signifying a pivotal development in the field of mobile security. [ABSTRACT FROM AUTHOR]

In this paper, we study the effects of spinning speed on the electrical, optical, structural, morphological, and gas sensing properties of thin films deposited on glass substrates by sol–gel spin coating, using copper acetate dihydrate as the precursor. The deposition of the films was carried out at varying spinning speeds from 1500 rpm to 2500 rpm to achieve different thicknesses ranging from 157 nm to 470 nm, respectively. The results revealed that the resistivity of the films decreased from 75.5 Ω·m to 42.5 Ω·m with the decrease in spinning speed. X-ray diffraction (XRD) studies demonstrated that the crystallite size varied in the range of 18.14–27.48 nm. The band gap of the samples was found to vary from 2 eV to 1.69 eV, revealing that these samples were suitable for gas sensing applications. Field-emission scanning microscopy (FESEM) studies showed that the prepared samples were porous in nature and were suitable for H2S gas detection. The films were examined at different operating temperatures with different concentrations of H2S gas. The results showed that the response toward hydrogen sulfide gas varied with varying thickness of the samples. The CuO thin films showed the highest response toward hydrogen sulfide gas at a temperature of 25°C. [ABSTRACT FROM AUTHOR]

The conversion of ambient mechanical vibrations into electricity using piezoelectric nanogenerators (PENGs) has garnered significant attention from researchers over the past few years, in light of its potential in wearable applications. The high flexibility and significant ferroelectricity of poly(vinylidene fluoride) (PVDF) make them the most promising candidates for PENG applications among polymer piezoelectric materials. In the present work, NiO nanoparticles were incorporated in different ratios into a PVDF matrix, and their potential for use in piezoelectric nanogenerators was investigated. The PVDF/NiO (5 wt.%) nanocomposite PENG exhibited the highest electrical output, with a 2.8-fold increase in open-circuit voltage and short-circuit current observed as compared to a bare PVDF-based PENG. However, a further increase in the compositional ratio of NiO led to a decrease in PENG output. The improved piezoelectricity in the PVDF/NiO (5 wt.%) nanocomposite is attributed to the enhanced polar phases and improved ferroelectricity of PVDF. Further confirmation of the improved piezoresponse was explored by measurement of the piezoelectric coefficient (d33) and dielectric study of the nanocomposites. The PENG electrical output was further simulated using the finite elemental method in COMSOL Multiphysics 5.5. The simulated results matched well with the experimental output, which confirmed the improved electrical performance of the PVDF/NiO nanocomposite-based PENGs. The enhanced performance of the nanocomposite PVDF film is attributed to the higher β phase in the PVDF. The efficiency of the PENG devices in motion-sensing applications was also explored. Different output voltage signals corresponding to different movements of the nanocomposite-based PENGs make the device compatible with sensor applications. [ABSTRACT FROM AUTHOR]

Excessive intake of nitrite causes serious health problems. Monitoring nitrite levels is necessary for protecting both human health and the environment. Therefore, the fabrication of sensors for rapid detection of nitrite was the aim of this work. We proposed a new method based on an electrochemical sensor prepared from polyrhodamine B (PRhB) coating deposited on polylactic acid modified carbon black (PLA-CB) electrode. The synthesized PRhB/PLA-CB sensor is selective and efficient for nitrite detection, which is based on the interaction between the dimethylamino group of PRhB and nitrite and it has both the advantages of simple preparation and low cost. In optimal experimental conditions, the results of cyclic voltammetry showed that PRhB/PLA-CB, showed significant improvement of the electro-catalytic performance (20%) compared to bare PLA-CB thanks to due to the large surface area and porosity provided by PLA-CB combined with the conductivity and catalytic activity of PRhB. The coating was characterized using the scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The effects of pH and scan rate on nitrite detection were evaluated. The modified electrodes exhibited a remarkable electro-catalytic performance with a wide linear range of 1-10000 µM and low limit of detection (LOD) of 0.342 µM and limit of quantification (LOQ) of 1.036 µM. The proposed sensor was used for the detection of nitrite in tap and commercial water showing good recovery results. [ABSTRACT FROM AUTHOR]

Excessive nitrite () addition poses a significant threat to food safety. Thus, it is desirable to construct a selective and dependable electrochemical sensor for the quantitative measurement of . In this study, an electrochemical sensor using nitrogen-rich porous carbon (NPC) derived from graphitic carbon nitride (g-C3N4) was developed for the quantitative detection of . The NPC synthesis involved a two-step process, namely polymerization and carbonization. The carefully designed polymerization method and optimal carbonization condition yielded an NPC material with a relatively high surface area of 593.36 m²·g⁻¹. Notably, NPC nanomaterials exhibited a high nitrogen content of 19.8%, comprising various nitrogen species (pyridinic N, pyrrolic N, and oxidized N) that are fully faradaic-active N species, leading to enhanced electrochemical properties and sensitivity. The calibration plot exhibited linearity within the concentration range of 2-3410 µM, LOD of 0.11 µM, a sensitivity of 11.32 µA·µM− 1 cm− 2 and further showed excellent adaptability in real sample analysis. This innovative way of creating electrochemical sensors from nitrogen-rich porous carbon materials broadens the scope of electroanalysis and provides a beneficial means of guaranteeing food safety. [ABSTRACT FROM AUTHOR]

The preparation of resistant ultrathin film (utf) hydrogels coated onto different working surfaces (e.g., fabrics) is paying increasing attention as an advantageous strategy for customizing their resultant properties. More specifically, poly(ethylene glycol) (PEG)‐based utf‐hydrogels are relevant for their superior biocompatibility or antibiofouling properties. However, promoting the generation of poly(ethylene glycol) dimethacrylate (PEGDMA) cross‐links ideally without the use of initiators or other cross‐link agents, which might compromise the final bioactivity of the system, is complicated. Moreover, the actual synthesis techniques used for the preparation of such utf‐hydrogels face important drawbacks like high scale‐up costs or important geometrical restrictions, completely hindering its technological transfer. Herein, for the first time and easy and technologically scalable technology is reported for the synthesis and direct deposition of PEGDMA400 utf‐hydrogels onto different substrates based on atmospheric pressure nanosecond pulsed plasma approach. The advantages of the technology are explored and discussed, reporting the ready‐to‐use transparent coating of fabrics. After washing the samples using washing programs of a commercial laundry machine, coatings are still well adhered, showing excellent stability. Finally, the resultant properties of PEGDMA400 utf‐hydrogels are exhaustively characterized using in operando conditions in order to elucidate their potential capabilities in the biomedical field. [ABSTRACT FROM AUTHOR]

Interactions between carbon nanotubes (CNTs) and fluid flows are central to the operation of several emerging nanotechnologies. In this paper, we explore the fluid-structure interaction of CNT micropillars in wall-bounded shear flows, relevant to recently developed microscale wall shear stress sensors. We monitor the deformation of CNT micropillars in channel flow as the flow rate and wall shear stress are gradually varied. We quantify how the micropillars bend at low wall shear stress, and then will commonly tilt abruptly from their base above a threshold wall shear stress, which is attributed to the lower density of the micropillars in this region. Some micropillars are observed to flutter rapidly between a vertical and horizontal position around this threshold wall shear stress, before settling to a tilted position as wall shear stress increases further. Tilted micropillars are found to kink sharply near their base, similar to the observed buckling near the base of CNT micropillars in compression. Upon reducing the flow rate, micropillars are found to fully recover from a near horizontal position to a near vertical position, even with repeated on–off cycling. At sufficiently high wall shear stress, the micropillars were found to detach at the catalyst particle-substrate interface. The mechanical response of CNT micropillars in airflow revealed by this study provides a basis for future development efforts and the accurate simulation of CNT micropillar wall shear stress sensors. [ABSTRACT FROM AUTHOR]

This paper introduces a new sensing approach utilizing a solid-solid phononic crystal (PnC) channel drop filter structure for the detection of varying molar fractions of Ethyl lactate within a mixture of Ethyl lactate and 2-butoxy ethanol. The sensor features a two-dimensional PnC constructed from poly methyl methacrylate as the background material, incorporating a regular arrangement of circular Tungsten columns. The design integrates a bus waveguide linked to two interconnected ring resonators, which are coupled to a drop waveguide. Each ring resonator is equipped with three strategically positioned pillars near the coupling region, allowing for the accommodation of varying concentrations of Ethyl lactate. The sensor's performance is significantly influenced by the ring resonators and the integrated pillars. It identifies specific resonance frequencies that shift in response to changes in Ethyl lactate concentrations within the resonators. The transmission resonance frequency exhibits valuable sensitivity to these concentration variations, reflecting the unique sound velocities and mass densities associated with each level of Ethyl lactate. The effectiveness of the proposed sensor is validated through coupled mode theory, demonstrating a close match with the device's observed behavior. The measured frequency range spans from 1.972 MHz to 1.979 MHz with a step size of 1 Hz. Notably, the sensor displays considerable characteristics, including an average quality factor of 90,613, an average sensitivity of 3816 Hz, an average figure of merit of 172, an average signal-to-noise ratio of 137, an average resolution of 22 Hz, an average damping ratio of 0.56 × 10− 5, and an average limit of detection of 34 × 10− 5. These results underscore the potential of the channel drop filter for the accurate detection of Ethyl lactate concentrations with high quality factor and sensitivity. The sensor can effectively identify variations in Ethyl lactate levels, which are prevalent in various applications, including pharmaceuticals and food additives. [ABSTRACT FROM AUTHOR]