UV-Vis Spectrometer Research Articles

Informing Near-Airport Satellite NO2 Retrievals Using Pandora Sky-Scanning Observations.

Airports are a large and growing source of NO x . Tracking airport-related emissions is especially difficult, as a portion of emissions are elevated above the surface. While satellite-based NO2 observations show hot-spots near airports, near-source retrievals often have large biases related to uncertainties in the NO2 vertical distribution and resultant air mass factors (AMF). Here we use observations from UV-vis spectrometers (Pandora 1S, SciGlob) deployed near the Atlanta Hartsfield-Jackson International airport from April 2020-May 2021 to assess the impact of aviation on NO2 vertical profiles. We show the first near-airport sky-scanning Pandora observations, which are used to distinguish the airport plume from the urban background. We find that increasing aviation leads to higher NO2 over the airport, and the enhancement is distributed across the mixed layer near-equally. We compare observed profiles with those modeled by the Goddard Earth Observing System composition forecast (GEOS-CF) system. We find that modeled profiles attribute a larger portion of the column closer to the surface and underestimate the NO2 mixing height. Observed profiles typically exhibited greater NO2 concentrations up to 2.5 km above ground level. Air mass factors (AMF) calculated using observations (AMFFused) are similar over Hartsfield-Jackson to those calculated using GEOS-CF (AMFGEOS-CF). The unexpected similarity in alternative AMFs is attributed to the altitude-dependent sensitivity of AMFFused to changes in NO2 concentration. Using either AMFFused or AMFGEOS-CF to evaluate TROPOMI NO2 against independent direct-sun observations produces consistent normalized mean differences of -22% and -29%, respectively. Overall, these results demonstrate the benefits of a combined ground and satellite-based approach for probing a complex distribution of NO x emissions in an urban area.

THE ANTIBACTERIAL ACTIVITY OF GUM ARABIC-COATED Mn-DOPED CuS NANOPRISMS

Novel nanoprism-shaped manganese-doped copper sulfide (Mn–CuS) was fabricated by two-phase colloidal method (Mn percentages = 0%, 1%, 3%, and 5%). The Mn–CuS was analyzed by XRD, FTIR, UV–Vis spectrometer, and TEM. The XRD shows that the hexagonal covellite copper sulfide peaks appeared at 2[Formula: see text], and [Formula: see text] for 0%, 1%, 3%, and 5% respectively, and orthorhombic chalcocite copper sulfide appeared at the peaks that are corresponding the planes (412), (275), (029) and (106). According to UV–Vis analysis, the optical absorption of manganese-doped copper sulfide 0%, 1%, 3%, and 5% clearly appeared in the UV–Vis region at 518, 440, 478, and 477[Formula: see text]nm respectively, and there are broad peaks for localized surface plasmon resonances (LSPR) of CuS located at 970, 1061, 1002, and 1006[Formula: see text]nm for Mn–CuS 0%, 1%, 3%, and 5%, respectively. The favored nanoprism-shaped sample (manganese-doped copper sulfide 1%) was coated with gum Arabic (GA) in order to decrease the cytotoxicity and enhance the biocompatibility. The antibacterial activity of manganese-doped copper sulfide and GA@Mn–CuS 1% nanostructure toward Staphylococcus aureus and Escherichia coli bacteria was determined by inhibition zone. It was found that the fabrecated Mn–CuS 1% nanoprisms were more active toward both E. coli and S. aureus bacteria and the doping enhanced the antibacterial activity.

Optical Study of Desmodium Elegan Mediated Silver Nanoparticles Using Tauc’s Equation

Green synthesis of metallic nanoparticles is more eco-friendly, simpler, and nontoxic as compared to chemical synthesis. Due to their thermal stability and good electrical conduction silver nanoparticles have significant importance these days. In the present work, the stable silver nanoparticles were prepared from the aqueous solution of AgNO3 by green synthesis technique in which the Desmodium elegan plant extract was used as a reducing and capping agent to convert Ag+ to Ag0. A UV-visible spectrometer is used in the range of 200 nm to 800 nm with a scanning speed of 200 nm per minute, the absorption band is found at a 450 nm peak that indicates the synthesis of silver nanoparticles. The particle size of the nanoparticles was in the range of 11 nm to 70 nm with an average of 45 nm and a spherical shape. Further confirmation of nano size, scanning electron microscopy (SEM) was also utilized for the size distribution and shape of the synthesized nanoparticles. The synthesized nanoparticles SEM studies show irregular spherical morphology with polydispersed trend and the average particle size was found at 45 nm. The absorption band for the synthesized sample was found at 450 nm peak. The bandgap energy was 2.84 eV estimated by Tauc’s equation. This indicates that the synthesized nanoparticles electrically lie in the range of semiconductors and can be used as a biosensor. This synthesis technique is a nontoxic technique so these particles may be used for water treatment.

Investigation on induced smectic phases in double hydrogen bond liquid crystal complexes derived from aromatic carboxylic acids: Experimental and quantum chemical approaches

In the present study, double Hydrogen bond liquid crystal (HBLC) complexes in different mole ratio (1:1 and 1:2) have been isolated from symmetrical aromatic dicarboxylic acid of non-mesogenic compound 1,3-Phenylenediacetic acid (1,3-PDA) and mesogenic compound 4-n-dodecyloxybenzoic acid (12 OBA). Fourier transform infrared Spectroscopy (FTIR) explores the presence of functional groups in the title complexes. Formation of H-bond between 1,3-PDA and 12 OBA is experimentally confirmed by observing the FTIR peak at 3639 cm−1 (1:1 ratio). Induced mesophases and its textures along with transition temperatures are analyzed using polarizing optical microscope (POM) and differential scanning calorimetry (DSC). The layered structures (smectic phases) and their molecular mechanism has been analyzed using density functional theory (DFT). Further, the establishment of H-bond in the title complex has been investigated with the aid of optimized geomentry, molecular electrostatic potential (MEP) and reduced density gradient (RDG) analysis. The band gap energy of title complex (1:1) is calculated by UV–Vis spectrometer and the same has been justified by HOMO-LUMO studies. Maximum absorption in the UV region and moderate bandgap energy (Eg = 4.22 eV) of the title complex clearly indicates its potential application in NLO, optoelectronics and laser tuning devices. In addition to that, LC parameters and its effect on mesophase are reported using experimental and computational methods.

An analysis of the synthesis, crystal structure, optical, spectroscopic, mechanical, self-focusing, and third-order nonlinear optical properties of Kojic acid single crystals

A single, excellent crystal of Kojic acid (KA) was developed utilising the traditional approach of gradual evaporation in a solution-growing procedure. A variety of characterisation techniques were utilised to evaluate the characteristics of the crystals generated. Single crystal x-ray diffraction (SXRD) was utilised to identify the crystal structure. The crystalline arrangement of the KA crystal was confirmed using a powder x-ray diffraction (PXRD) analysis. Experiments with UV–vis spectrometers revealed that the KA crystal has a lower wavelength at which it blocks UV light but has outstanding light transmission throughout the visible spectrum. The KA single crystal has an energy band gap (Eg) of 2.5 eV. The Z-scan method was used to examine the third order susceptibility, nonlinear refraction, and nonlinear absorption coefficient of the synthesised KA crystal. The dielectric characteristics and AC conductivity were examined, with a particular emphasis on their connection to resistance at room temperature. The presence of appreciable levels of kojic acid was confirmed by energy-dispersive spectrometry. The crystal’s thermal behaviour was investigated using differential thermal analysis (DTA) and thermogravimetric (TG) methods. The nucleation parameters and controlled nucleation rate were calculated using normal theoretical research methods.

Studies of third order nonlinearity and thermal diffusivity of C3OC dye using thermal lens technique

An FT-IR spectrometer and a UV–Visible spectrometer were utilised in order to characterise the Cyanidin-3-O-glucoside chloride (C3OC) dye. The dye’s thermally induced optical nonlinearity was measured in a dimethylformamide solvent using an adjustable diode-pumped solid-state (DPSS) laser at 473 nm. The optical response was measured using the Z-scan technique. The dye showed negative and large nonlinear refractive index) NRX) values, with high nonlinear absorption coefficients (NBO). Because of its ability to change with concentration, the NRX is a viable candidate for applications in the field of nonlinear optics. Thermal lens (THS) technique was used to investigate thermo-optical properties and the NRX. The optical limiter capabilities of the C3OC dye are being investigated as a potential use.

Low-temperature/room-temperature gas sensing application for NO2 gas by SnO2 and Ni doped SnO2 nanostructures synthesized by sol-gel method

Gas sensors are the attentive parts for the day-to-day applications in advanced manufacturing, chemical industries and advanced applications need the better performing materials. SnO2 (wide band gap-3.27eV, n-type semiconductor) and Ni-doped SnO2 are the suitable materials for gas sensing in the fields of forward-looking technology. Pure and Ni-doped SnO2 particles were synthesized by sol-gel method and started with 0.2 mol of SnCl2, added with 2 ml of acetic acid, and pH controlled by the addition of 8 mol NaOH, till pH reaches desired value and Ni is doped. Finally washed, dried, and calcined at 400° C. The prepared pure and Ni(0.02 and 0.04 mol)-doped SnO2 nanostructures were characterized by XRD, EDAX, DSC, and SEM techniques. Average crystallite size is calculated by XRD and varied from 8 to 5 nm. Morphology shows difference, while the Ni concentrations changed. Particle size is estimated by transmission electron microscope (TEM), found to be 8–12 nm and well correlated with XRD analysis. The Energy gap is calculated with the UV–Vis spectrometer, and values are 3.21, 3.60, and 3.56 eV. Finally, the application part was carried out for NO2 gas sensing at a low level of 7–19 parts per million (PPM) at 40 °C, response and recovery times are 6 and 9 min respectively for all PPMs. Sensitivity of the samples of pure and Ni doped samples have 99 to 99.9 and 80 %. Pure and 0.02 mol Ni doped samples have the good achievement for sensitivity and 0.04 mol Ni doping has increase in conductance.

Antiproliferative Activity of Green Process Synthesized Epipremnum Aureum Silver Nanoparticles Against Breast Cancer Mcf-7 Cells

Breast cancer (BC) is one of the most severe cancers among women globally. Local recurrence of cancer after surgery is usually seen as a poor predictor of prognosis. Cancer treatment has been significantly transformed by the progress made in nanotechnology, and nanoparticles have emerged as pivotal components in this domain. Metal nanoparticles are produced using plant extract in green synthesis or eco-friendly techniques for the stabilizing and reducing substance. The current research study synthesizes silver nanoparticles (AgNPs) from Epipremnum aureum leaf extract using the green synthesis method and its evaluations using UV-Vis, FTIR, XRD, SEM, and EDX characterization techniques. The EA-AgNPs exhibit a significant absorption peak at wavelength 420 nm, which confirms the AgNP's presence by UV-visible spectrometer. FTIR spectrum reveals the strong band at 1586.020 cm-1 confirming the O-H group presence. The stretching and bending modes of vibration of the NO32- a sharp band represented molecule at 1382.987 cm-1 and a very tiny band at 1272.241, 1077.355 cm-1. The XRD spectrum exclusively showed Ag peaks, with no additional chemical contaminants, signifying the sample's purity, and the average particle size was 12.92 nm. MTT assay result observed high cytotoxic activity of EA-AgNPs against MCF-7 cells with IC50= 0.1106 µg/ml. This research study aims to preliminary investigate the in-vitro antiproliferative activity of green process synthesized Epipremnum Aureum silver nanoparticles (EA-AgNPs) against breast cancer cell line (MCF-7).

Structural, magnetic and electrical studies on nickel doped copper ferrite synthesized using sol-gel method

Nickel doped copper ferrite nanoparticles NixCu1-xFe2O4(x = 0.1, 0.3, 0.5, 0.7, and 0.9) have been prepared through well known sol-gel technique. Numerous analytical methods, including the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and powder X-ray diffractometer (XRD), were used to analyze the synthesized materials. Synthesized sample XRD patterns reveal the single phase development of the spinel crystalline structure in the absence of any contaminant. The concentration of Ni ions rises with a corresponding decrease in crystallite size. Scanning electron microscopy (SEM) was also used to assess the microstructure. By using UV–Visible spectrometer an optical absorbance and through FTIR, two of ferrite's distinctive bands were verified. The M-H loops show that when the concentration of nickel ions increases, saturation magnetization varies. The Cyclic-Voltameter was used to perform the ionic electrochemical analysis. The NixCu1-xFe2O4 nanopowder's enhanced magnetic characteristics suggest that these substances would make good candidates for magnetic catalysts.

Structural, electrical and magnetic studies on Zn doped MnFe2O4 nanoparticles with via Sol-Gel approach

A manganese ferrite (MnFe2O4) nanoparticle is prepared through sol-gel method. The various concentration of Zn (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9) was added to the initial solutions. Through X-Ray diffraction examinations results confirmed the cubic spinel structure of Mn1-xZnxFe2O4 and have larger crystallite size. The functional analysis is obtained through Fourier transform infrared spectroscopy (FTIR) analysis and it is indicated that Fe-O, Mn-O, and Zn-O vibrational bands. The optical analysis carried out through UV–visible spectrometer. The surface features with morphology and its content of elements in the samples were found through scanning electron microscope (SEM) with energy dispersive (EDAX) analysis. The energy analysis carried out through Xray Photo electro absorption (XPS) analysis. The detailed magnetic characteristics of the resulting samples such as cohersivity (Hc), magnetization (Ms), retentivity (Hr), squareness ratio (SQR) and anisotripic constant (Ki) were found through vibrating sample magnetometer (VSM), shows good magnetic property, multi grain wall and the strong dependents of Zn . The dielectric related parameters like dielectric constant for real and imaginary components, loss tangent with AC conductivity with respect to applied frequency are enhanced dielectric constant and at the same time it reduces the dielectric loss tangent discussed through LCR measurement. The electrochemical behaviour of the samples was tested through cyclic voltameter setup. Finally, concluded with their merits and demerits.

Exploring the Synthesis of Novel Sillenite Bi12SnO20: Effect of Calcination Temperature on the Phase Formation and Catalytic Performance

Sillenite materials have been the focus of intense research in recent years due to their unique properties and distinct structure with the I23 space group. This electronic structure has reflected high-quality applications and results for some environmental processes such as photocatalysis. This paper investigates the synthesis of a new sillenite, Bi12SnO20, and its characteristics, emphasizing its potential for photocatalytic applications. The sillenite Bi12SnO20 has been synthesized through the co-precipitation method by mixing the appropriate ratio of Bi and Sn ions. The obtained particles after precipitation and drying were characterized by thermogravimetric analysis (TGA) and then calcined at different temperatures based on this analysis. The phase has been identified by structural analysis using X-ray diffraction (XRD), and its morphology after identification was carried out by scanning electron microscopy (SEM). The calcination temperature has been found to have a critical role in obtaining the phase, where the phase was found to be formed at temperatures between 310 and 400 °C and changed to other phases within higher temperatures. The physicochemical properties of this sillenite were also studied by Fourier-transform infrared spectroscopy (FTIR) and UV Visible Spectrometer (UV-Vis). To study the obtained phases at different calcination temperatures, performance testing was performed under visible light to remove different contaminants, which are Tetracycline, Bisphenol A, and Rhodamine B. The phase Bi12SnO20 obtained at 350 °C with a catalyst dose of 1 g/L showed the highest performance for removing these pollutants with concentrations of 20 mg/L, with an efficiency of almost 100% within 2 h. This work will be useful as an important resource and strategy for the development of this sillenite material in its pure phase.

Co3O4 nanoparticles synthesized with rotten-grape extract for use in supercapacitors and oxygen evolution devices

Phytochemicals in grape fruit juice have never been considered as potential sources of surface modification, shape modification, and energy storage. In our study, we demonstrate the hydrothermal synthesis of Co3O4 nanostructures from grape fruit extracts. X-ray diffraction analysis revealed that Co3O4 nanostructures exhibit a cubic phase, while Fourier transform infrared spectroscopy identified several functional groups. An analysis of Co3O4 nanostructures using a scanning electron microscope revealed that uniformly distributed nanoparticles of Co3O4 were trapped in the carbon content of the spices during calcination. UV–visible spectrometer analysis of Co3O4 nanostructures reveals a wide range of optical bands. It was found that one mL of grape fruit juice provided the lowest optical band gap of 2.51 eV for Co3O4 nanostructures. Nanostructures of Co3O4 were studied under alkaline conditions for use in supercapacitors and oxygen evolution reactions. An aqueous solution containing 1 mL of assisted Co3O4 nanostructures exhibited an overpotential of 290 mV at a current density of 10 mA cm−2 in 1 M KOH. In addition, they showed a Tafel slope of 80 mV dec−1. When dissolved in 3 M KOH electrolyte, grape fruit juice assisted Co3O4 nanostructures showed a specific capacitance of 867 F/g at 1.5 A/g in 3 M KOH aqueous solution. A specific capacitance retention percentage of about 101.1 % was achieved after 40000 galvanic charge-discharge cycles. It has been shown that the total photochemistry of biomass waste can be tuned and enhanced to enhance the functional properties of nanostructures derived from rotten grape fruit extract in order to develop functional materials with high performance for a wide range of applications.

Effect of gamma and ultraviolet irradiation on the optical properties of copper oxide nanostructured thin films by chemical spray pyrolysis

Nanostructured copper oxide thin films were grown by the chemical spray pyrolysis (CSP) technique. Utilizing a homemade spray pyrolysis method, thin films are created. This work investigates the role of gamma ray and ultraviolet ray irradiation on the optical properties of copper oxide thin films(CuO) prepared. In this framework, used different substrate temperatures 300 °C, 350 °C, and 400 °C for the layers were grown on glass for the prepared CuO thin films. UV–visible spectrometer, field emission scanning electron microscopy (FE-SEM) and X-ray diffraction patterns(XRD) measurements were all used to characterize the samples. The UV–visible spectroscopy showed a decrease in the absorbance and the optical band gap of CuO thin films with the increase in the higher substrate temperatures before irradiation. Additionally, surface plasmon resonance peaks (λSPR) were observed at 329 nm. FE-SEM images revealed spherical-like shapes with an average diameter range of 48 nm,56 nm and 62 nm for 300 °C, 350 °C, and 400 °C, respectively. An analysis of X-rays revealed that CuO thin films contained the crystallographic planes of a monoclinic and an orthorhombic crystal system. Also, when samples were exposed to gamma and UVC radiation, the absorbance intensity of CuO thin films increased, but the optical band gap decreased.

Synthesis and characterisation of superior AC/ZnO NPs biocomposite for hexavalent chromium Cr(VI) adsorption

This study aims to synthesize biocomposite by combining banana stem activated carbon (AC) and ZnO Nanoparticles (NPs) to evaluate their adsorption potential towards hexavalent chromium (Cr (VI)) (20 mg/L). The AC used was successfully synthesized by an impregnation method using phosphoric acid (H3PO4) for 24 h, followed by a carbonization method. ZnO NPs were synthesized using the direct precipitation method using zinc acetate dihydrate (0.2 M) and KOH (0.4 M) as precursors. The AC/ZnO NPs biocomposite was fabricated using the mechanical alloying method at a frequency of 10 Hz for 30 min. The FTIR results show that both adsorbents, namely pure AC and AC/ZnO NPs have abundant functional groups. XRD results show the adsorbent is amorphous with pure AC at 89.95% and AC/ZnO NPs biocomosite at 56.49%. SEM results showed that the morphology of AC resembled crushed bovine bone marrow, and the morphology of ZnO NPs showed a marshmallow-like shape. The UV–vis spectrometer test results show that at the absorption peak of 350 nm the Cr (VI) removal efficiency slowly decreases and disappears at a dose variation of 1.5 g pure AC, 2 g biocomposite AC/ZnO NPs, and 2 g pure AC with Cr (VI) removal efficiency of 99.61%, 99.64%, and 99.83% respectively. Finally, we can report that the high degradation ability for Cr (VI) can be related to thesharp peak of –C=O group, reduced ΔLO−TO, and smaller average crystallite size in AC/ZnO NPs biocomposite.

Laser enhanced photothermal effect of silver nanoparticles synthesized by chemical and green method on Gram-positive and Gram-negative bacteria

PurposeThe antibacterial properties of silver nanoparticles (AgNPs) are extensively identified. In large quantities, they might be harmful. So many fields of nanotechnology have shown a great deal of interest in the development of an environmentally friendly, efficient method for synthesizing metal nanoparticles. Because of its antibacterial and antifungal properties toward a wide range of microbes, chitosan silver nanoparticles (AgNPs@Cs) constitute a newly developing class of bio-nanostructured hybrid materials. Furthermore, the use of photothermal therapy (PTT) has been suggested as a means of elimination of germs. These light-stimulated treatments are minimally invasive and have a few side effects. In the present work, the antibacterial effect of AgNPs at low concentrations; prepared by chemical and green methods as antimicrobial and photothermal agents in photothermal therapy; with laser irradiation were explored as combined treatment against MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae.MethodsSilver nanoparticles were produced in two ways. First, by sodium borohydrides, second, by chitosan (as a natural eco-friendly reducing, and capping agent). The nanostructure of AgNPs and AgNPs@Cs was confirmed by UV–visible spectrometer, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIRs), and direct light scattering (DLS). The antibacterial activity of the prepared nanoparticles and the laser irradiation was tested against three bacterial species of zoonotic importance; MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and was evaluated by measuring their minimum inhibitory concentrations (MIC).ResultsSilver nanoparticles produced by the two methods had spherical shapes with nearly the same particle size. The analysis of DLS showed that AgNPs were very stable with zeta potential − 28.8 mv, and 47.7 mv by chemical and chitosan synthesis, respectively. Furthermore, AgNPs@Cs showed higher antibacterial activity toward the tested bacterial species than AgNPs by chemical method. Additionally, the bacterial viability using photothermal laser therapy was reduced compared to laser and AgNPs alone. The bactericidal activities were higher when laser diode was coupled with AgNPs@Cs than by chemical reduction.ConclusionThe laser combined treatment had a higher antimicrobial effect than AgNPs alone or laser irradiation alone.

Fabrication, catalytic activity, metal sensing ability and electrochemical evaluation of nano silver particles for supercapacitor applications

In this work, stable, spherical silver nanoparticles (MAgNp) were prepared via a green synthesis method using flowers of Myristica fragrans (nutmeg). This flower is abundant in phytochemicals such as saponins that can be utilized as reductants to produce silver nanoparticles. The synthesized nanoparticles were examined using a variety of physico-chemical methods, including transmission electron microscopy (TEM), Dynamic light scattering (DLS), elemental dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV–VIS spectrometer. EDX study confirmed the crystalline and face-centered cubic (FCC) structure of AgNP. The majority of particles are present with a higher percentage intensity at an average size of 58.77 nm as revealed in the TEM image, PDI was found to be 0.055. MAgNPs demonstrated perfect activity in the catalytic degradation of methylene blue dye (88 %) and para-nitrophenol (98 %), both anthropogenic pollutants. These nanoparticles were further used as plasmonic sensors to detect heavy metals like Fe(II) and Hg(II) in an aqueous solution. The minimum detection limit was found to be 0.2 mM for Hg(II) and 10 μM for Fe(II) with good linearity. The electrochemical properties of MAgNPs were studied using a carbon supercapacitor electrode coated with MAgNPs. Results from cyclic voltammetry were also determined, and they showed a high specific capacitance of 41 F/gm at 5 mV/s scan rate.

Application of a UV-vis spectrometer to investigate the effect of dissolution media on the diffusivity of small molecules and proteins

To date, the commonly used methods for diffusion coefficient measurements have some hurdles that prevent them from being widely applied in pharmaceutical laboratories. This study aimed to modify a method developed by di Cagno et al. based on the use of a UV-Vis spectrometer and apply the method to investigate the effect of dissolution media on the diffusivity of small molecules and proteins. A total of five small molecules and two proteins in different aqueous media and polymer solutions were investigated in this study. By attaching a 3D-printed cover with an open slit to a standard UV-Vis cuvette, the incident UV light could only pass through the open slit to measure the local drug concentration. During the diffusion experiment, drug molecules diffused from the cuvette bottom to the slit. According to the concentration measured as a function of time, diffusion coefficient was calculated based on Fick's law of diffusion using the analytical and numerical approaches. As a result, diffusion coefficients could be accurately measured with high reproducibility. The results also suggested that different media could affect the diffusion coefficients of small molecules by < 10% and proteins by < 15%. Since the UV-Vis spectrometer is a routine instrument, this method can potentially be employed by many pharmaceutical laboratories for diffusion coefficient measurements.

Photodetector Devices: Investigation of ZnO Thin Films Fabricated via SILAR Technique on Various Substrates:

The synthesis of photodetectors for ZnO nanostructure films on various substrates, including p-type (100) silicon (Si), and porous silicon (pSi), has been achieved through the utilization of a straightforward technique known as the successive ionic layer adsorption and reaction (SILAR) method. To analyze the optical properties, surface morphology, and crystal structure of the ZnO layers, UV-Vis spectrometers, field emission scanning electron microscopes (FESEM), and X-ray diffraction (XRD) were employed. The characterization of the ZnO samples revealed that the number of SILAR cycles has a significant impact on the morphology and optical band gap of the synthesized layer. The Fourier-transform infrared (FTIR) spectrum successfully detected the distinctive extended vibration mode of ZnO. By conducting 20 cycles, high-quality hexagonal ZnO was obtained. The responsivity of the planar ZnO on silicon (ZnO/Si) and ZnO on the porous silicon (ZnO/pSi) surface exhibited variations depending on the substrate surface and bias voltage. The results indicated that the (ZnO/pSi) heterojunction demonstrated a high response in the visible range (350–850 nm) at a low bias voltage. On the other hand, the (ZnO/Si) photodetector displayed a high sensitivity of 666.66% at a low voltage of 1V in comparison to the (ZnO/pSi) photodetector, which exhibited a sensitivity of 483%.

Investigation of structural, optical, photocatalytic, and antibacterial properties of ZnO doped GO nanoparticles for environment applications.

As a result of their unique and novel properties, nanocomposites have found applications in a wide variety of fields. The purpose of this study is to demonstrate the ability to synthesize nanoparticles consisting of zinc oxide (ZnO) and graphene oxide (GO) via sol-gel techniques. An x-ray diffractometer (XRD) as well as a UV-visible spectrometer were used to determine the crystalline and optical characteristics of the prepared samples. A hexagonal wurtzite crystal structure was observed in both pure ZnO nanoparticles and those that contain GO based on XRD results. It was estimated that the average crystallite size is based on the broadening of x-ray lines. In comparison with pure ZnO, the antimicrobial properties were enhanced when GO was incorporated with ZnO. In addition, experiments on the absorption edge indicated the presence of a red shift as a result of the incorporation of GO. When GO is incorporated in quantitative amounts, the bandgap value of pure ZnO decreased. FTIR spectra exhibit a band of absorption at 486 cm-1, which confirms Zn-O stretching in both samples. SEM images reveal a random pattern of structural features on the surface of the prepared samples. According to the EDX spectrum, pure GO nanoparticles and those doped with ZnO contain 61%-64% zinc and 32%-34% oxygen, respectively. When annealed at a higher temperature, ZnO NPs produced more H2 with a narrower bandgap than before annealing. In addition, methyl blue (MB) was used as an example of an organic compound in order to investigate the potential photocatalytic properties of nanoparticles with ZnO doped GO. In addition to DPPH assays, ZnO nanoparticles and ZnO doped GO nanoparticles were tested for their ability to scavenge free radicals. Comparing ZnO doped GO NPs with pure ZnO, these nanoparticles showed increased antioxidant activity. Based on the increased zone of inhibition observed for pure ZnO and ZnO doped GO (5, 10, 50, and 100 mg/mL), the antibacterial activity of pure ZnO and ZnO doped GO is concentration dependent. A detailed discussion of the results of the study demonstrated that ZnO doped GO and pure ZnO are toxic in different ways depending on how long they survive in degreased Zebrafish embryos and how fast they decompose. RESEARCH HIGHLIGHTS: The scope of the manuscript was under the results of the study confirmed that both nanoparticles exhibited concentration dependent antioxidative activity. Determined that 89% of methyl orange dye can be degraded photocatalytically. ZnO nanoparticles were found to be 74.86% antioxidant at a concentration of 50 g/mL in the present study. At a concentration of 50 g/mL, ZnO doped GO NPs showed 79.1% antioxidant activity. Photocatalytic degradation mechanism scheme is implicit in the photoexcited charge carrier transportation path is observed for all the samples. Survival rate of zebrafish embryos was shown to decrease with increasing concentrations of ZnO and zinc oxide plus GO nanoparticles.

Characterization of Nanoparticles in Drinking Water Using Field-Flow Fractionation Coupled with Multi-Angle Light Scattering and Inductively Coupled Plasma Mass Spectrometry

The current absence of well-established and standardized methods for characterizing submicrometer- and nano-sized particles in water samples presents a significant analytical challenge. With the increasing utilization of nanomaterials, the potential for unintended exposure escalates. The widespread and persistent pollution of water by micro- and nanoplastics globally is a concern that demands attention, not only to reduce pollution but also to develop methods for analyzing these pollutants. Additionally, the analysis of naturally occurring nano entities such as bubbles and colloidal matter poses challenges due to the lack of systematic and consistent methodologies. This study presents Asymmetric Flow Field-Flow Fractionation (AF4) separation coupled with a UV-VIS spectrometer followed by Multi-Angle Light Scattering (MALS) for detection and size characterization of nanometric entities. It is coupled with an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) for elemental analysis. Water samples from different sources, such as untreated mountain spring water, groundwater, and bottled drinking water, were analyzed. The system was calibrated using pure particle standards of different metallic compositions. Our study demonstrates the capability of AF4-UV-MALS-ICP-MS to detect metals such as Al, Ba, Cu, and Zn in particles of around 200 nm diameter and Mg associated with very small particles between 1.5 and 10 nm in different drinking water samples.