Nanoparticles Of Different Sizes Research Articles

Brittle–ductile transition and toughening of silica glass via Ni nanoparticle incorporation at a small volume fraction

The brittleness of glass significantly limits its application, and an effective solution is to impart ductility to it. In this study, Ni nanoparticles of different sizes were dispersed in SiO2 glass to investigate the effect of the particle size on the ductility of glass. Ni nanoparticles (0.5 vol. %) of two sizes (average particle sizes: 119 and 30 nm) were precipitated in the SiO2 glass by sintering on Ni nanoparticle-dispersed SiO2 glass powder. The fracture toughness obtained by microcantilever beam tests was significantly enhanced from 0.71 MPam1/2 for unmodified glass to 1.02 and 2.03 MPa m1/2, respectively, for the glass samples incorporated with small (30 nm) and larger Ni nanoparticles (119 nm). The fracture surface energy increased significantly with the dispersion of the Ni nanoparticles in the glass matrix, despite their small volume fraction (0.5 vol. %). Moreover, a cup–cone structure indicative of ductile fracture was formed in the glass containing large Ni nanoparticles, whereas the glass dispersed with smaller Ni nanoparticles exhibited brittle fracture. These results indicate large stress dissipation in the former owing to its ductility. A theoretical approach based on the generation and movement of dislocations was employed to rationalize the particle-size-dependent fracture characteristics of the metal-particle-incorporated glass. Thus, we developed a cost-effective method to significantly enhance the fracture toughness of glass by imparting ductility via the dispersion of a small amount of metallic nanoparticles.

Shape control of deformable charge-patterned nanoparticles.

Deformable nanoparticles (NPs) offer unprecedented opportunities as dynamic building blocks that can spontaneously reconfigure during assembly in response to environmental cues. Designing reconfigurable materials based on deformable NPs hinges on an understanding of the shapes that can be engineered in these NPs. We solve for the low-energy shapes of charge-patterned deformable NPs by using molecular dynamics-based simulated annealing to minimize a coarse-grained model Hamiltonian characterized with NP elastic and electrostatic energies subject to a volume constraint. We show that deformable spherical NPs of radius 50nm whose surface is tailored with octahedrally distributed charged patches and double-cap charged patches adapt their shape differently in response to changes in surface charge coverage and ionic strength. We find shape transitions to rounded octahedra, faceted octahedra, faceted bowls, oblate spheroids, spherocylinders, dented beans, and dimpled rounded bowls. We demonstrate that similar shape transitions can be achieved in deformable NPs of different sizes. The effects of counterion condensation on the free-energetic drive associated with the observed deformations are examined via Manning model calculations that utilize simulation-derived estimates for the NP Coulomb energy under salt-free conditions. The charge-pattern-based shape control of deformable NPs has implications for the design of responsive nanocontainers and for assembling reconfigurable materials whose functionality hinges on the shape-shifting properties of their nanoscale building blocks.

Green Synthesis and Antibacterial Activity of Silver Nanoparticles: A Review

The purpose of this study was to determine the effect of silver nanoparticles (AgNPs) from different green synthesis medium and their various particle sizes on antibacterial activity. The article review method compares the results of 11 studies obtained from the PubMed database, Web of Science, and ScienceDirect indexed by Scopus in the last five years. The search was conducted based on the phrases nanoparticles, antibacterial, Green synthesis, and AgNPs. Green synthesis of AgNPs with various plant extracts produces different sizes of nanoparticles. The smallest size AgNPs were obtained in the range of 5-15 nm and an average of 13 nm extracted using the leaves of the Pacific Yew tree (Taxus brevifolia). Meanwhile, AgNPs with the best antibacterial effectiveness were obtained from the Blume flower extract (Wedelia urticifolia) measuring less than 30 nm providing a zone of inhibition for S. aureus, K. pneumoniae, E. coli, and P. aeruginosa bacteria.

3D-Bioprinted Phantom with Human Skin Phototypes for Biomedical Optics.

3D-bioprinted skin-mimicking phantoms with skin colors ranging across the Fitzpatrick scale are reported. These tools can help understand the impact of skin phototypes on biomedical optics. Synthetic melanin nanoparticles of different sizes (70-500nm) and clusters are fabricated to mimic the optical behavior of melanosome. The absorption coefficient and reduced scattering coefficient of the phantoms are comparable to real human skin. Further the melanin content and distribution in the phantoms versus real human skins are validated via photoacoustic (PA) imaging. The PA signal of the phantom can be improved by: 1) increasing melanin size (3-450-fold), 2) increasing clustering (2-10.5-fold), and 3) increasing concentration (1.3-8-fold). Then, multiple biomedical optics tools (e.g., PA, fluorescence imaging, and photothermal therapy) are used to understand the impact of skin tone on these modalities. These well-defined 3D-bioprinted phantoms may have value in translating biomedical optics and reducing racial bias.

Minimizing the Optical Illusion of Nanoparticles in Single Cells Using Four-Dimensional Cuboid Multiangle Illumination-Based Light-Sheet Super-Resolution Imaging.

Although light-sheet-based super-resolution microscopy is an excellent detection technique for biological samples because of minimal photodamage, uneven light paths due to solid-angle illumination limits it, resulting in an optical illusion. Furthermore, the optical illusion limits the observations of individual molecules in diffraction. In this study, a four-dimensional cuboid multiangle illumination-based light-sheet super-resolution (4D CMLS) imaging system was developed to minimize optical illusions in cells. The lab-built 4D CMLS imaging system was integrated with total internal reflection fluorescence and a differential interference contrast microscope. A specially designed rotatable cuboid prism simply overcame the optical illusion by rotating a specimen on the prism to change the direction of light coming from an illumination lens. 4D CMLS reconstructed images of nanoparticles of different sizes were acquired in multi-illumination angles of 0°, 90°, 180°, and 270°. Additionally, a 4D multiangle illumination-based algorithm was created to select the optimal illumination angle by combining three-dimensional super-resolution imaging with multiangle observation, even in the presence of obstacles. The 4D CMLS imaging method demonstrates the in-depth 4D observation of samples at an optimum angle that can be used in various applications, such as single-molecule and subcellular organelle observations in single cells at subdiffraction limit resolutions that describe the scenario of nature.

Silver nanoparticles with excellent biocompatibility block pseudotyped SARS-CoV-2 in the presence of lung surfactant.

Silver (Ag) is known to possess antimicrobial properties which is commonly attributed to soluble Ag ions. Here, we showed that Ag nanoparticles (NPs) potently inhibited SARS-CoV-2 infection using two different pseudovirus neutralization assays. We also evaluated a set of Ag nanoparticles of different sizes with varying surface properties, including polyvinylpyrrolidone (PVP)-coated and poly (ethylene glycol) (PEG)-modified Ag nanoparticles, and found that only the bare (unmodified) nanoparticles were able to prevent virus infection. For comparison, TiO2 nanoparticles failed to intercept the virus. Proteins and lipids may adsorb to nanoparticles forming a so-called bio-corona; however, Ag nanoparticles pre-incubated with pulmonary surfactant retained their ability to block virus infection in the present model. Furthermore, the secondary structure of the spike protein of SARS-CoV-2 was perturbed by the Ag nanoparticles, but not by the ionic control (AgNO3) nor by the TiO2 nanoparticles. Finally, Ag nanoparticles were shown to be non-cytotoxic towards the human lung epithelial cell line BEAS-2B and this was confirmed by using primary human nasal epithelial cells. These results further support that Ag nanoparticles may find use as anti-viral agents.

Decoupling of dust cloud and embedding plasma for high electron depletion in nanodusty plasmas

In recent years nanoparticles have become key technological products, e.g., as coatings with tunable optical gap in third generation solar cells, as nanocrystals for photonic applications, and as pharmaceutical nanocarriers. In particle sources, that use reactive, nanodusty plasmas, a high dust density changes the properties of the dusty plasma compared to a dust free plasma considerably, as electron depletion leads to a reduced number of free electrons. This is called the Havnes effect and was central for the understanding of the famous spokes in Saturns rings. We see here, that it is also important for technological applications. Using self excited dust density waves (DDW) as a diagnostic tool, we completely characterize an argon discharge with embedded amorphous hydrocarbon nanoparticles of different size and density. The results show, that electron depletion governs the charge of dust grains, while the size of the particles has only a weak influence. The ion density and electric potential profile are almost independent of both, dust size as well as dust density. This suggests, that the rf generated plasma and the dust cloud seem to coexist and coupling of both is weak.

RNA with chemotherapeutic base analogues as a dual-functional anti-cancer drug

ABSTRACT Nanoparticles of different sizes formulated with unmodified RNA and Protamine differentially engage Toll-like Receptors (TLRs) and activate innate immune responses in vitro. Here, we report that similar differential immunostimulation that depends on the nanoparticle sizes is induced in vivo in wild type as well as in humanized mice. In addition, we found that the schedule of injections strongly affects the magnitude of the immune response. Immunostimulating 130 nm nanoparticles composed of RNA and Protamine can promote lung metastasis clearance but provides no control of subcutaneous tumors in a CT26 tumor model. We further enhanced the therapeutic capacity of Protamine-RNA nanoparticles by incorporating chemotherapeutic base analogues in the RNA; we coined these immunochemotherapeutic RNAs (icRNAs). Protamine-icRNA nanoparticles were successful at controlling established subcutaneous CT26 and B16 tumors as well as orthotopic glioblastoma. These data indicate that icRNAs are promising cancer therapies, which warrants their further validation for use in the clinic.

Plasmon-Enhanced Ultraviolet Luminescence in Colloid Solutions and Nanostructures Based on Aluminum and ZnO Nanoparticles.

Aluminum nanoparticles attract scientific interest as a promising low-cost material with strong plasmon resonance in the ultraviolet region, which can be used in various fields of photonics. In this paper, for the first time, ultraviolet luminescence of zinc oxide nanoparticles in colloid solutions and nanostructure films in the presence of plasmonic aluminum nanoparticles 60 nm in size with a metal core and an aluminum oxide shell were studied. Mixture colloids of ZnO and Al nanoparticles in isopropyl alcohol solution with concentrations from 0.022 to 0.44 g/L and 0.057 to 0.00285 g/L, correspondingly, were investigated. The enhancement of up to 300% of ZnO emission at 377 nm in colloids mixtures with metal nanoparticles due to formation of Al-ZnO complex agglomerates was achieved. Plasmon nanostructures with different configurations of layers, such as Al on the surface of ZnO, ZnO on Al, sandwich-like structure and samples prepared from a colloidal mixture of ZnO and Al nanoparticles, were fabricated by microplotter printing. We demonstrated that photoluminescence can be boosted 2.4-fold in nanostructures prepared from a colloidal mixture of ZnO and Al nanoparticles, whereas the sandwich-like structure gave only 1.1 times the amplification of luminescence. Calculated theoretical models of photoluminescence enhancement of ideal and weak emitters near aluminum nanoparticles of different sizes showed comparable results with the obtained experimental data.

Near field and far field plasmonic enhancements with bilayers of different dimensions AgNPs@DLC for improved current density in silicon solar

The effect of a bilayer of different dimension silver nanoparticles (Ag NPs) on light trapping in silicon solar cells is investigated. Here, we report on the improved performance of silicon solar cells by integrating two layers of silver nanoparticles of different sizes. We experimentally examine the plasmonic near-field and far-field effects of bilayer Ag NPs embedded within an anti-reflective DLC layer on silicon solar cells' optical and electrical characteristics. Field-Emission Scanning Electron Microscopy drove the two-dimensional differences in the size of Ag NPs. The surface plasmon resonance of the two-dimensional nanoparticles was estimated from the absorption optical spectra. External quantum efficiency measurements showed that near-field or far-field plasmonic effects altered with the Ag NPs size. The development of far fields was confirmed by measuring the solar cell performance under AM 1.5 G illumination. The impact of the far-field in the cell containing two layers of Ag NPs, which outer layer is larger dimensions NPs, improves the current density up to 38.4 mA/cm2 (by 70% compared to the bare reference cell).

Studies of the Photoprotection of Radiata Pine Wood Using Photocatalytic Nanoparticles

In this work, TiO2 and ZnO nanoparticles of different sizes and crystallographic configuration were used to protect wood surfaces against UV radiation. The sizes and levels of photoactivity of the nanoparticles were measured in vitro by transmittance electron microscopy and electron paramagnetic resonance spectroscopy, and then they were impregnated into radiata pine samples. The production of aromatic radicals, absorbance of UV and visible light, and chemical and color changes of treated and untreated wood surfaces were assessed after UV irradiation. Results show that nanoparticles that were less photoactive were better at reducing the production of organic radicals and the chemical and color changes on wood surfaces subjected to UV. Similarly, smaller nanoparticles (40 nm) were better at reducing photochemical reactions than larger (100 nm) nanoparticles. In terms of the crystallographic configuration of nanoparticles, differences in the production of phenoxy radicals were verified only for short-term exposure. Previous research revealed that certain levels of photoactivity in TiO2 nanoparticles may contribute to decreases in the photodegradation of wood surfaces possibly by an electron sink mechanism. Our observations indicate that this is unlikely to occur in the presence of highly photoactive nanoparticles.

Pitfalls in methods to study colocalization of nanoparticles in mouse macrophage lysosomes

BackgroundIn the field of nanoscience there is an increasing interest to follow dynamics of nanoparticles (NP) in cells with an emphasis on endo-lysosomal pathways and long-term NP fate. During our research on this topic, we encountered several pitfalls, which can bias the experimental outcome. We address some of these pitfalls and suggest possible solutions. The accuracy of fluorescence microscopy methods has an important role in obtaining insights into NP interactions with lysosomes at the single cell level including quantification of NP uptake in a specific cell type.MethodsHere we use J774A.1 cells as a model for professional phagocytes. We expose them to fluorescently-labelled amorphous silica NP with different sizes and quantify the colocalization of fluorescently-labelled NP with lysosomes over time. We focus on confocal laser scanning microscopy (CLSM) to obtain 3D spatial information and follow live cell imaging to study NP colocalization with lysosomes.ResultsWe evaluate different experimental parameters that can bias the colocalization coefficients (i.e., Pearson’s and Manders’), such as the interference of phenol red in the cell culture medium with the fluorescence intensity and image post-processing (effect of spatial resolution, optical slice thickness, pixel saturation and bit depth). Additionally, we determine the correlation coefficients for NP entering the lysosomes under four different experimental set-ups. First, we found out that not only Pearson’s, but also Manders’ correlation coefficient should be considered in lysosome-NP colocalization studies; second, there is a difference in NP colocalization when using NP of different sizes and fluorescence dyes and last, the correlation coefficients might change depending on live-cell and fixed-cell imaging set-up.ConclusionsThe results summarize detailed steps and recommendations for the experimental design, staining, sample preparation and imaging to improve the reproducibility of colocalization studies between the NP and lysosomes.Graphical

Size characterization of plasmonic nanoparticles with dark-field single particle spectrophotometry

Plasmonic nanoparticles are widely used in multiple scientific and industrial applications. Although many synthesis methods have been reported in the literature throughout the last decade, controlling the size and shape of large populations still remains as a challenge. As size and shape variations have a strong impact in their plasmonic properties, the need to have metrological techniques to accurately characterize their morphological features is peremptory. We present a new optical method referred as Dark-Field Single Particle Spectrophotometry which is able to measure the individual sizes of thousands of particles with nanometric accuracy in just a couple of minutes. Our method also features an easy sample preparation, a straightforward experimental setup inspired on a customized optical microscope, and a measurement protocol simple enough to be carried out by untrained technicians. As a proof of concept, thousands of spherical nanoparticles of different sizes have been measured, and after a direct comparison with metrological gold standard electron microscopy, a discrepancy of 3% has been attested. Although its feasibility has been demonstrated on spherical nanoparticles, the true strengthness of the method is that it can be generalized also to nanoparticles with arbitrary shapes and geometries, thus representing an advantageous alternative to the gold-standard electron microscopy.

Ponderomotive forces in the system of two nanoparticles

Mechanical consequences of electromagnetic interaction of two nanoparticles have been modeled and simulated. It has been shown that the local field enhancement effect in the studied system causes the appearance of the local field gradients. As a consequence, the local field gradients can lead to ponderomotive forces acting on the nanoparticles near their surface. In the work, the model describing the phenomena has been developed. The model is based on the near-field interaction in the self-consistent system and the effective susceptibility concept. Using the model distribution of the local field in the system of two different-sized nanoparticles has been calculated and ponderomotive forces directions and values were simulated. It has been shown that in the system of two different-sized nanoparticles the forces act mainly on the surface of the bigger nanoparticle and for some systems, the value of its density per volume unit may acquire up to several tens of nano newtons. Possible application of the results to the study of biological systems has been also discussed.

SMC complexes can traverse physical roadblocks bigger than their ring size.

Ring-shaped structural maintenance of chromosomes (SMC) complexes like condensin and cohesin extrude loops of DNA. It remains, however, unclear how they can extrude DNA loops in chromatin that is bound with proteins. Here, we use invitro single-molecule visualization to show that nucleosomes, RNA polymerase, and dCas9 pose virtually no barrier to loop extrusion by yeast condensin. We find that even DNA-bound nanoparticles as large as 200nm, much bigger than the SMC ring size, also translocate into DNA loops during extrusion by condensin and cohesin. This even occurs for a single-chain version of cohesin in which the ring-forming subunits are covalently linked and cannot open to entrap DNA. The data show that SMC-driven loop extrusion has surprisingly little difficulty in accommodating large roadblocks into the loop. The findings also show that the extruded DNA does not pass through the SMC ring (pseudo)topologically, hence pointing to a nontopological mechanism for DNA loop extrusion.

Effect of graphene oxide nanoparticles on viability of BAP3 hybridoma cells

Graphene oxide (GO) is a promising material, which is likely to find applications in the fields of medicine and biotechnology. However, the current knowledge of its influence on human organism is limited. Even less information is available on the effects of GO on the cell lines widely used in biotechnology. The aim of this work is to describe the interaction between GO nanoparticles and BAP3 hybridoma cells which produce anti-human-PSG1 IgG, in vitro. We studied the effect of GO nanoparticles on cell viability and the intensity of internalization (adhesion) of nanoparticles by the cells. We used GO nanoparticles of different size, with surface being functionalized by linear or branched PEG (GO-PEG). The PEG coating level was 20% (by mass). The following nanoparticle concentrations were used: 5 g/mL and 25 g/mL. The BAP3 cells were cultured in a 48-well cell culture plates in serum-free DCCM-1 media in the presence of GO nanoparticles. The cells were cultured for 24 hours at 37 С and 5% СО2. Cell viability was assessed by a flow cytometer utilizing Zombie Aqua (ZA) staining. Internalization (adhesion) of nanoparticles was monitored using a flow cytometer by GO fluorescense in the samples (ex = 488 nm). Moreover, interactions between hybridoma cells and GO nanoparticles were visualized by EVOS M5000 visualization system, which included an inverted fluorescent microscope.
 We demonstrated that GO nanoparticles possess a cytotoxic effect when applied at high concentration (25 g/mL). The highest cytotoxic effect is caused by GO nanoparticles coated with linear PEG. The degree of nanoparticle internalization (adhesion) was shown to be significantly lower when the particles were present at lower (5 g/mL) concentration. Internalization (adhesion) of nanoparticles of smaller size was more abundant. Furthermore, these nanoparticles were shown to have a stronger cytotoxic effect compared to larger particles. In general, cytotoxicity of GO nanoparticles decreases with increasing size, which is especially evident if the fact that the mean effective diameter of the nanoparticles coated with branched PEG is considered larger than their linear PEG-coated counterparts. The data obtained allow us to draw a correlation between the cytotoxic effect of GO nanoparticles and the level of their internalization (adhesion) by the cells. In general, this work concerns some novel aspects of interaction between GO nanoparticles and hybridoma cells.

Combinatorial nanoparticle patterns assembled by photovoltaic optoelectronic tweezers

Photovoltaic optoelectronic tweezers (PVOTs) have been proven to be an efficient tool for the manipulation and massive assembly of micro/nano-objects. The technique relies on strong electric fields produced by certain ferroelectric materials upon illumination due to the bulk photovoltaic effect (customarily LiNbO3:Fe). Despite the rapid development of PVOTs and the achievement of high-quality 1D and 2D particle patterning, research efforts aimed at the fabrication of combinatorial structures made up of multiple types of particles have been scarce. Here, we have established the working principles of three different methods to tackle this pending challenge. To that end, dielectrophoresis and/or electrophoresis acting on neutral and charged particles, respectively, have been suitably exploited. Simple mixed structures combining metallic and dielectric nanoparticles of different sizes have been obtained. The results lay the groundwork for future fabrication of more complex combinatorial structures by PVOT, where micro/nanoparticles are the basic building blocks of miniaturized functional devices.

The effects of co-exposures of Zea mays plant to the photon-upconversion nanoparticles; does the size or composition play an important role?

This work thoroughly describes how three different types of photon-upconversion nanoparticles (UCNPs) that differ in size or composition influence a model plant Zea mays. This plant was treated with an aqueous dispersion of nanoparticles in a hydroponic short-term toxicity test (168 h) in three different concentrations (0.5, 5, and 25 μg/mL of yttrium). The plants were exposed in a single toxicity test as well as in so-called co-exposures where the plants were in direct contact with the nanoparticles of different sizes (hydrodynamic diameter 25.9 nm and 58.2 nm) or with different compositions (doped with gadolinium and thulium or with erbium ions) at the same time. After the exposure, basic macroscopic toxicity end-points were monitored. The translocation of nanoparticles across the whole plant was evaluated by Laser-Induced Breakdown Spectroscopy (lateral resolution of 26 and 100 μm) and by photon-upconversion microscanning (lateral resolution of 40 μm). Also, the total content of elements contained in plants was measured for the underground (root and coleoptile) and above-ground (primary leaf) parts separately using Inductively-Coupled Plasma Optical Emission Spectroscopy. Afterwards, bioaccumulation and translocation factors were evaluated. Our results indicated significant toxicity of all tested exposures groups for Z. mays plant. The main bioaccumulation site was the underground part, whereas the transfer to the above-ground part was minimal. Also, the UCNPs showed a low stability and led to a notable release of ions.

Cytocompatibility of oleic acid modified iron oxide nanoparticles

Our long-term goal is to utilize oleic acid-modified iron oxide (OA-Fe3O4) nanoparticles embedded into a monoglyceride matrix for remote drug release utilizing an alternating magnetic field (AMF). However, the toxicological behavior of OA-Fe3O4 nanoparticles when in contact with biological tissues remains unknown. The size, shape, and surface morphology of OA-Fe3O4 nanoparticles prepared in our laboratory were evaluated using SEM and TEM. These data show that the OA-Fe3O4 nanoparticle preparations do not form aggregates and maintain the expected size and shape. We also used HTB-19, a human mammary tumor cell line, to assay the cytocompatibility of OA-Fe3O4 nanoparticles of different sizes (5, 10, 20, and 30 nm) at varying doses (6.25, 12.5, 25, and 50 µg/mL) using CytoTox-Glo™ cytotoxicity kit and phase-contrast inverted microscopy. These results indicate that there is no appreciable cytotoxicity at the lowest (6.25 µg/mL) concentration. Even the highest (50 µg/mL) concentration used in our study show > 75% cell viability. Microscopic morphological assessment performed using phase-contrast inverted microscopy revealed internalization of the nanoparticles and proliferation of cells in the presence of the OA-Fe3O4 nanoparticles. Taken together, our results show that OA-Fe3O4 nanoparticles are a safe and promising biocompatible excipient for drug delivery.

Magnetic Relaxation Switch Sensor Based on Magnetophoresis and "T-Hg(II)-T" Signal Amplification.

In this study, we designed a magnetic relaxation switch (MRS) sensor combined with magnetophoresis technology (MS-MRS), which helps solve the problems of traditional MRS sensors. The sensor is based on a new combined magnet and is composed of small magnetic blocks and iron sheets that can rapidly separate magnetic nanoparticles of different sizes within 5 min. The MS-MRS sensor consists of aptamer-functionalized magnetic nanoparticles (diameter: 200 nm) (MNP200-Apt), complementary DNA-functionalized magnetic nanoparticles (diameter: 20 nm) (MNP20-cDNA), and a combined magnet ("M2" magnet). The MNP200-Apt probe could be separated by an "M2" magnet but the MNP20-cDNA probe could not. To further improve the sensitivity of the sensor, we successfully constructed an MS-MRS-Hg sensor based on the "T-Hg(II)-T" specific recognition that aggregated MNP20-cDNA probes to amplify the relaxation signal. The detection working range of the MS-MRS sensor is 0.5-100 ng/mL and that of the MS-MRS-Hg sensor is 0.05-100 ng/mL. Their limit of detection (LOD) values are 0.15 and 0.01 ng/mL, respectively. The relative recoveries of the MS-MRS and MS-MRS-Hg sensors are 95.2-119.5% and 93.1-113.1%, respectively. These results indicate that the proposed sensors have a high accuracy level.