In this paper, a bio-sensing setup for investigating hepatitis B virus deoxyribonucleic acid (HBV DNA) diagnosis including rapid testing and field effect transistor (FET) in label free assay is ...proposed. The FET biosensor was fabricated by molybdenum doped ZnO nanowires (NWs) in easy method and cost-free approach. The materialized NWs were synthesized by physical vapor deposition (PVD) growth mechanism. The molybdenum dopant could bring about vacancy sites for DNA adsorption and electric charge transfer. The capability of the fabricated biosensor was evaluated by investigating the PCR-verified samples known as True Positive (TP), True Negative (TN), False Positive (FP) and False Negative (FN). The FET biosensor could materialize the clinical tests on samples TP, TN, FP and FN and could distinguish the clinical samples from each other. The designed biosensor showed more precision than the PCR-outcomes by exhibiting more sensitivity on labeled samples known as FN. This research has analytical and comparative study on fabricated biosensor performance. The achieved results show that the biosensor had significant response to samples which have not been carefully detected by PCR test. The fabricated biosensor showed high accuracy, precision, sensitivity, specificity and reproducibility for differentiating (TP), (TN), (FP) and (FN) samples from healthy and normal sample. The response sensitivity was calculated and biosensor showed a detection limit (LOD) of 1 pM. The biosensor demonstrated high response and satisfied signal in the concentration ranges from 1 pM to 10 μM.
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•A FET biosensor based on Mo doped ZnO NWs for HBV detection in label free was reported.•Complementary DNA target was diagnosed in concentration ranges from 1 pM to 10 μM.•Sensitivity response of the HBV biosensor showed a limit of detection (LOD) of 1 pM.•Biosensor could distinguish the clinical samples TP, TN, FP and FN from each other.•Results showed that the FET biosensor had better response in comparison to PCR test.
In fractures where surface fluctuations are large compared to their aperture (narrow fractures), the flow is forced to move in tortuous paths that produce additional viscous friction and are subject ...to inertia effects. We consider the relation between the magnitude of surface roughness and the onset of inertial effects in the pressure driving the flow through a single open fracture. We performed experiments systematically varying the average aperture of the open fracture and covering a wide range of Reynolds numbers. For each aperture, we analyze the data in terms of the Forchheimer equation and show that the critical Reynolds number, defined as the Reynolds number at which inertial effects contribute 10% of the total pressure losses, is highly correlated with the roughness of the surface. In particular, we show that significant inertial effects appear earlier as the relative importance of surface roughness increases. Finally, we present results showing that the magnitude of the deviations in the pressure field compared to a linear profile, taken at different points in the fracture along the flow direction, is directly related to the relative surface roughness of the fracture.
Key Points
Surface roughness leads to an early onset of inertial effects
Surface roughness leads to an increase in spatial pressure fluctuations
The critical Reynolds number correlates with normalized surface roughness
In this study, we investigate the optical absorption of a planar superlattice comprising alternatively arranged two-dimensional Transition Metal DiChalcogenide semiconductors. Within a semi-classical ...model and using the Dirac-like equation in the presence of light interaction as a perturbation, we obtained the governing Hamiltonian. Using this Hamiltonian, we derived a fully analytical relationship for the absorption coefficient of the structure. By calculating the effective mass for different bands and using the Drude-Lorentz model, our approach is able to determine the oscillator strength and the effective refractive index of the structure. We found that the spin-orbit coupling has important effect on the absorption coefficient and energy bands where it reduces the absorption coefficient of the structure from typical value of Formula: see text-Formula: see text, also the valence band experiences a significant blue shift, while the conduction band shows minor changes due to spin orbit coupling. Moreover, the role of incident light angle and light polarization were studied in details at different valleys of Formula: see text and Formula: see text. The most important finding is that by changing the polarization of incident light, it is possible to increase the absorption coefficients of Formula: see text and Formula: see text valleys by up to 30 times. For light propagation direction close to perpendicular to the plane of the superlattice, the right-circular polarization is absorbed only by Formula: see text valley in contrast to the left-circular polarization, which is absorbed by the Formula: see text valley. Our model might be used to design newly developed 2D optovalleytronic devices.
WTe2 is one of the exciting and outstanding semimetallic members of TMDCs, which has attracted immense attention for manipulating light propagation due to its inherent optical anisotropy and ...hyperbolic characteristic in the infrared frequency range. We investigate the dependence of the reflectance and transmittance of structures with a single and double WTe2 thin film in terms of frequency and polarization angle of the incident wave. We find rich behaviors in the optical response of these structures due to their anisotropic permittivity tensors. Furthermore, we analyze the polarization state of transmitted and reflected waves through these structures. We demonstrate that these structures provide the ability to achieve desired polarization rotation for outgoing waves by tuning the frequency and polarization angle of the incident wave with respect to the principal axes of WTe2 thin film. In particular, we elucidate the essential relevance of the optical response and polarization rotation of the double thin film structure to the in-plain twist angle of WTe2 thin films. We explain that this structure permits comprehensive control of the polarization rotation of the outgoing waves by adjusting the twist angle of thin films. The proposed structure can be employed as an efficient light manipulator with the aim of application in communication, imaging, and information processing.
Novel ternary Zinc cadmium sulfate/Manganese ferrite/Graphene oxide (ZnCdS/MnFe2O4/GO) nanocomposites were synthesized via a hydrothermal process in this study, with a focus on optimizing the ...graphene oxide (GO) content. Characterization techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), UV–visible spectroscopy, photoluminescence (PL) spectroscopy, and N2 physisorption were employed. The investigation revealed that nanocomposites with 3 wt% GO content exhibited superior adsorption capacity and visible-light photocatalytic activity for the removal of Methylene blue (MB) from wastewater. The ZnCdS/MnFe2O4/GO 3 % composite demonstrated exceptional stability and efficiency, achieving nearly 96 % MB removal within 220 min. Moreover, the ZnCdS/MnFe2O4/GO 3 % nanocomposites displayed promising reusability with sustained photocatalytic activity over multiple degradation-regeneration cycles. These findings highlight the potential of ternary GO/ZnCdS/MnFe2O4 nanocomposites as effective photocatalysts for the practical remediation of organic pollutants in wastewater systems.
Theoretical comparative study has been done on the optical absorption of planar graphene superlattice with Thue-Morse and Fibonacci sequence formed by patterning graphene sheet on a heterosubstrate ...as Sio2 and h-BN. A numerical method along with analytical approach is presented to obtain electronic structure and in particular, wavefunctions in these structures together with optical absorption. A tunable optical transitions between minibands is observed based on engineering structural parameters in both superlattice structures. Considerable optical absorption is obtained for Thue-Morse superlattice (TGSL) and Fibonacci superlattice (FGSL). Through detailed study a comparison between two structures is done to show their potential for photonics application.
•Planar Thue-Morse and Fibonacci graphene superlattices has been investigated.•Analytical expression for optical absorption from two-band model is derived.•The role of different statuses of polarization as circular and linear are considered.•The comparison between two FGSL and TGSL optical response been studied in details.
In this study, NiFe2O4 and NiFe2O4@Cu nanoparticles (NPs) were synthesized based on the co-precipitation method. The formation of cubic NiFe2O4 and NiFe2O4@Cu NPs was confirmed by the Bragg ...reflections in XRD analysis. The SEM images showed the distribution of the irregularly shaped agglomeration of NiFe2O4 and NiFe2O4@Cu NPs. The size distributions of the NiFe2O4@Cu samples with two different core shell thicknesses were mostly about 10.39 and 13.31 nm. The superparamagnetic nature of the synthesized NPs was verified by VSM at room temperature, and the NPs’ saturation magnetization was found to be 37.04 emu/g, which was reduced after shielding the core. Furthermore, to investigate the cancer cell viability and cytotoxicity of the NPs on MCF7 breast cancer cells, different concentrations of NPs were examined. The response of the NiFe2O4@Cu NPs to the laser light irradiations indicated that these NPs can potentially be used for biomedical applications such as photothermal treatment.
The exchange integral in the magnetic response of a spherical metallic iron (Fe) and nickel (Ni) nanoparticle is theoretically studied by using Monte Carlo simulations. To this end, using the ...nanoparticles model in spherical coordinates, we compute magnetization, magnetic susceptibility, specific heat, internal energy, and hysteresis loop over a wide range of temperatures for an Fe and Ni nanoparticle with a size of about 2 nm. The phase transition temperatures are interpolated versus the exchange parameters, and it is observed that the dependence on the coupling parameter is completely linear. Moreover, from the susceptibility results of the samples, the sharpest peak with the least fluctuation gives us the most appropriate Curie temperature and exchange integral for this system. However, the peak related to the heat capacity is also in the Curie temperature range. From the internal energy results, it can be understood that with the increase in phase transition and interaction, the system reaches equilibrium. The magnetic coercive field and remanent magnetization caused by nanoparticles indicate superparamagnetic properties at room temperature. At the end, the obtained results allow us to theoretically determine the magnetic properties of spherical nanoparticles and pave the way for the development of nanoparticles for many applications.
We present a room temperature Graphene Quantum Dots (GQDs) based optical gas sensor for carbon dioxide gas detection. GQDs were prepared by a hydrothermal method and deposited on a quartz substrate ...using a drop-casting technique. The size of synthesized GQDs is in the range of 10 to 20 nm. GQDs films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), photoluminescence (PL) and UV-Vis absorption spectroscopy. The gas sensing measurements were studied using optical absorbance changes of GQDs film upon exposure to different concentrations of CO2 gas. The as-prepared gas sensor showed a significant sensitivity with a partially reversible response to CO2 gas, indicating its great potential to pave a way toward a novel CO2 gas sensor.
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