Using Ultraviolet-visible Research Articles

Synthesis and transport potential study of A2B type double chain amphiphilic architectures

AbstractThe inefficient delivery of drugs having low efficacy to their target sites is significantly hampering the treatment of many diseases and putting enormous pressure on the healthcare system. In this endeavor, the non‐ionic amphiphilic nanotransporters are drawing increasing attention over the past decades. Herein, we report the synthesis of a newer A2B type non‐ionic double chain amphiphilic nanotransporters by using dimethyl 5‐hydroxy isophthalate based central core prepared by propargylation followed by ester hydrolysis. The core was subsequently decorated with hydrophobic alkyl (C8/C20/perfluoro alkylated Cf8) chains via esterification. Monomethoxy polyethylene glycol (mPEG) moiety (Mn: 750/1000) was then incorporated by click chemistry approach to confer hydrophilicity. The aggregation behavior of synthesized non‐ionic amphiphiles in aqueous medium was evaluated by using dynamic light scattering (DLS) and fluorescence spectroscopy. The nanotransport potential of the synthesized amphiphiles was studied by using model hydrophobic guests, that is, the dye Nile red and the drugs nimodipine and curcumin by using ultraviolet–visible (UV/Vis) and fluorescence spectroscopic techniques. Evaluation of the viability of amphiphiles synthesized against HeLa cells showed them to be well tolerated up to the concentration studied. Stimuli responsive release of encapsulated Nile red from the inner core of amphiphile was successfully carried out in the presence of an immobilized enzyme Candida antarctica lipase (Novozym 435). In nutshell, the results obtained from this study may be instrumental in the design and development of promising nanotransporters for biomedical applications.

The drug delivery of Ciclopirox anticancer by γ-graphyne and its boron nitride analogue: electronic study via DFT

ABSTRACT A substantial amount of scholarly inquiry has focused on the advancement of innovative methodologies for drug administration. In this research, both graphyne (GY) and BN-analog GY (BNY) nanosheets are presented. The study focuses on the carbon allotrope GY. Density Functional Theory (DFT) calculations were used to assess how GY, BNY, and the anticancer drug ciclopirox (CPX) interact with one another. It was observed that the inherent capability of pristine GY to augment CPX adsorption is intensified by the involvement of nitrogen (N) and boron (B) atoms. Furthermore, examination using Ultraviolet–Visible (UV-Vis) analysis exhibited a shift towards less energetic states, corresponding to longer wavelengths. Moreover, the interaction between CPX and BNY displayed chemical reactivity, rendering it conducive for forming bonds at the adsorption site. Additionally, a thorough investigation via the Atoms-In-Molecules (AIM) analysis furnished a more profound comprehension of the associations between the drug and the nanosheet. Notably robust connections between CPX and BNY were detected. As a consequence, the potential of BNY to function as a viable transporter for CPX in the realm of drug delivery was substantiated.

Tanning Wastewater Sterilization in the Dark and Sunlight Using Psidium guajava Leaf-Derived Copper Oxide Nanoparticles and Their Characteristics.

Employing Psidium guajava (P. guajava) extract from leaves, copper oxide nanoparticles (CuO NPs), likewise referred to as cupric oxide and renowned for their sustainable and harmless biogenesis, have the possibility of being useful for the purification of pollutants as well as for medicinal purposes. The current study examined the generated CuO NPs and their physical qualities by using ultraviolet-visible (UV) spectroscopy. The distinctive peak at 265 nm of the CuO NP production was originally seen. Additionally, an X-ray diffraction (XRD) investigation was conducted to identify the crystalline arrangement of the produced CuO NPs, and a Fourier transform infrared (FTIR) spectroscopy examination was performed to validate the functional compounds of the CuO NPs. Additionally, the synthesized nanoparticles' catalytic activities (wastewater treatment) were analyzed in dark and sunlight modes. The catalytic properties of CuO NPs in total darkness resulted in 64.21% discoloration, whereas exposure to sunshine increased the nanomaterials' catalyst performance to 92.31%. By lowering Cr(VI), Ni, Pb, Co, and Cd in sewage by proportions of 91.4, 80.8, 68.26, 73.25, and 72.4% accordingly, the CuO NP demonstrated its effectiveness as a nanosorbent. Total suspended solids (TSS), total dissolved solids (TDS), chemical oxygen demand (COD), biological demand for oxygen (BOD), and conductance were all successfully reduced by nanotreatment of tanning effluents, with proportion reductions of 93.24, 88.62, 94.21, 87.5, and 98.3%, correspondingly.

Synthesis of efficient light harvesting Cr, N Co-doped TiO2 nanoparticles for enhanced visible light photocatalytic degradation of xanthene dyes; eosin yellow and rose bengal.

To solve the problem of water pollution, using environment friendly and cost effective method in short time is the need of hour. In this work, chromium (Cr) and nitrogen (N) co-doped TiO2 nanoparticles were synthesized and were used for the photocatalytic degradation of dyes under visible light. The synergistic effect of metal and non-metal co-dopants added would result in appropriate reduction of band gap {from 3.2 eVof TiO2 to 2.67eV}, decrease in recombination rate of charge carriers by trapping electrons and holes, and in better light harvesting capacity. Nanoparticles were synthesized by sol-gel method and characterized using ultraviolet-visible (UV-VIS) spectroscopy, fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), zeta potential, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET)analysis, field emission scanning electron microscopy (FE-SEM), and RAMAN spectroscopy. Eosin yellow (EY) and rose bengal (RB) were subjected to photocatalytic degradation under solar light to check the photocatalytic activity of the synthesized nanoparticles. Effects of dye concentration, the concentration of nanoparticles, time, and pH were investigated to optimize the parameters. The results obtained were remarkable for 20ppm EY solution took 10min using 1 gL-1 NPs at pH 3 and 10ppm RB solution took 5min using 0.75 gL-1 NPs at pH 5.78 (original pH) for complete degradation. Kinetics studies were also performed and both dyes followed pseudo-second-order kinetics with R2 values 0.99312 and 0.99712 for EY and RB, respectively. The study of degraded products was conducted using high-performance liquid chromatography (HPLC) hyphenated with electron spray ionization mass spectroscopy (ESI-MS) (LC-MS) and possible degradation pathways were made for both dyes. A reusability test was also performed showing the efficiency of the particles was up to 88% after 3 cycles of use. These notable results can be attributed to the efficient removal of organic pollutants using the proposed dopants in this study.

Goji-Berry-Mediated Green Synthesis of Gold Nanoparticles and Their Promising Effect on Reducing Oxidative Stress and Inflammation in Experimental Hyperglycemia.

The present report focuses on a rapid and convenient method applicable in the green synthesis of gold nanoparticles (AuNPs) using goji berry (Lycium barbarum-LB) extracts rich in antioxidant compounds, as well as on the structural analysis and evaluation of the induced antioxidant protection and anti-inflammatory effects of the synthesized gold nanoparticles upon endothelial cells (HUVECs) exposed to hyperglycemia. The synthesized AuNPs were characterized using ultraviolet-visible (UV-Vis) spectroscopy and transmission electron microscopy (TEM), whereas the presence of bioactive compounds from the L. barbarum fruit extract on the surface of the nanoparticles was confirmed using Fourier transform infrared spectroscopy (FTIR). The antioxidant activity of the biosynthesized gold nanoparticles was evaluated on the HUVEC cell line. The results reveal that AuNPs with a predominantly spherical shape and an average size of 30 nm were obtained. The UV-Vis spectrum showed a characteristic absorption band at λmax = 536 nm of AuNPs. FTIR analysis revealed the presence of phenolic acids, flavonoids and carotenoids acting as capping and stabilizing agents of AuNPs. Both the L. barbarum extract and AuNPs were well tolerated by HUVECs, increased the antioxidant defense and decreased the production of inflammatory cytokines induced via hyperglycemia-mediated oxidative damage.

Bacterial Polysaccharide-Stabilized Silver Nanoparticles Photocatalytically Decolorize Azo Dyes.

Bacterial polysaccharide is advantageous over plant, algal, and fungal polysaccharides in terms of stability, non-toxicity, and biodegradable nature. In addition, bacterial cell wall polysaccharide(CPs) is very little explored compared to exopolysaccharide. In this study, CPs have been isolated from thermotolerant Chryseobacterium geocarposphaerae DD3 (CPs3) from textile industry dye effluent. Structural characterization of the CPs was done by different techniques, viz., scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). CPs3 demonstrated compact non-porous amorphous surface composed of evenly distributed macromolecular lumps. TGA revealed a high thermostability (~ 350°C) of the polysaccharide. FTIR and NMR confirm the polysaccharidic nature of the polymer, consisting of glucose units linked by both β-(1 → 3) and β-(1 → 4) glycosidic bonds. The functional properties of CPs3 were evaluated for industrial use as additive, especially antibacterial, emulsification, and flocculation capacities. A single-step green synthesis of silver nanoparticle (AgNP) was performed using CPs3. AgNP was characterized using ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), AFM, and particle size analyses. The CPs3-stabilized AgNP exhibited potential photocatalytic activity against a broad range of azo dyes, congo red (88.33 ± 0.48%), methyl red (76.81 ± 1.03%), and malachite green (47.34 ± 0.90%) after only 3h of reaction. According to our knowledge, this is the first report on CPs from C. geocarposphaerae. The results demonstrated multifunctionality of CPs3 in both prospective, CPs3 as additive in biotechnology industry as well as Cps3-stabilized AgNP for bioremediation of azo dye.

The Spatial Distribution Characteristics of Dissolved Organic Matter (DOM) in Sediments and Water Quality of Wuli Lake, Taihu Lake Basin, China

Based on a field investigation conducted in May 2019, the spatial distribution characteristics of dissolved organic matter (DOM) in sediments of Wuli Lake in the Taihu Lake basin were analyzed using ultraviolet-visible (UV-Vis) absorption spectroscopy and three-dimensional fluorescence spectroscopy. The results showed that: (1) The overall water quality of West Wuli Lake was significantly better than that of East Wuli Lake. The water transparency, measured in Secchi depth (SD), of West Wuli Lake was higher than that of East Wuli Lake, while the suspended solids (SS), total nitrogen (TN), total phosphorus (TP) and chlorophyll a (Chl-a) were higher in East Wuli Lake than in West Wuli Lake. (2) The spatial distribution of a(350), M and SR values of DOM in surface sediment in Wuli Lake differed; a(350) values were highest in the northwestern part of Wuli Lake, while M and SR values were highest in the eastern part. The mean value of SR in Wuli Lake was 2.12 ± 0.67, indicating that the DOM contained more authigenic humus; the mean M value was less than 3.5, indicating that the proportion of humic acid was higher than that of fulvic acid. (3) The ranges of the biogenic index (BIX), the humic index (HIX) and the fluorescence index (FI) of surface sediments in Wuli Lake were 0.64~0.85, 3.79~4.84 and 1.72~1.84, respectively, indicating that surface sediments in Wuli Lake were characterized by authigenic sources, and the humic components of DOM in sediments were characterized by a dual contribution from terrestrial and endogenous sources.

Hybrid rGO-AgNPs Conductive Ink for Inkjet Printed Flexible Humidity Sensor

Due to the challenging dispersion of graphene in aqueous media, organic solvents are commonly used in conductive graphene inks. This will result in safety issues and environmental pollution. In this study, we demonstrated a green approach of graphene ink preparation through one-pot synthesis reaction that produce a hybrid reduced graphene oxide (rGO)-silver nanoparticles (AgNPs), with deionized water as solvent. The synthesized rGO-AgNPs was monitored using ultraviolet–visible (UV-Vis) spectroscopy and fourier transform infrared (FTIR). A stable dispersion of rGO-AgNPs ink was confirmed through UV-Vis analysis. FTIR result showed the removal and the reduction in the intensities of absorption bands of oxygen-containing functional groups, which indicated that graphene oxide (GO) has been successfully reduced to rGO in the hybrid ink. The printed film of rGO-AgNPs exhibited a high conductivity of 1.50 × 104 S/cm, proven that the electrical performance of the hybrid ink has been improved as compared to previously reported GO-based ink. Printed into interdigitated electrode (IDE), the impressive characteristic of our hybrid ink performed well as a high-sensitivity flexible humidity sensor.

Isolation of Flavonoids Compounds from Akalifa (Acalypha wilkesiana Muell. Arc.) Plant Leaves

Flavonoid compounds from the leaves of Akalifa (Acalypha wilkesiana Muell. Arc.) have been extracted with maceration by methanol solvent, then added with ethyl acetate and partition extracted with n-hexane. 6% HCl acidifies the concentrated methanol extract, then partition extracted with chloroform. The concentrated chloroform extract was separated by column chromatography with silica gel 40 as the stationary phase and n-hexane: ethyl acetate 90:10; 80:20; 70:30; 60:40; 50:50 (v/v) as the mobile phase. The compounds were purified with TLC preparative yielding tawny paste weighing 4 mg with Rf= 0.42 with eluent n-hexane: ethyl acetate 60:40 (v/v). The identified analysis by using Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infra Red Spectroscopy (FT-IR), and Proton Nuclear Magnetic Resonance (1H-NMR) Spectroscopy was estimated as a flavonoid is an isoflavone.

CHARACTERIZATION OF ENERGY BAND GAP THIN FILM BaTiO3 – BaZr0.5Ti0.5O3 USING DIFUSION REFLECTANCE SPECTROSCOPY (DRS) METHOD

Ferroelectric material is a dielectric material that has a high dielectric constant value so that it can be made in the form of thin films. Its application is based on electro-optical properties, one of which is the infrared thermal switch. This paper aims to determine the bandgap energy (Eg) of a 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 thin film. The 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 thin film is a semiconductor material with the valence band and conduction band separated by an energy bandgap (Eg). Thin films of 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 were grown on FTO substrates using the sol-gel method. The films of 0.3BaTiO3 – 0.7BaZr0.5Ti0.5O3 were annealed at different temperatures of 700°C, 750°C and 800°C within 1 hour. Characterization was carried out using Ultra Violet Visible (UV-Vis) spectroscopy to determine Eg using the Diffusion Reflectance Spectroscopy (DRS) method. The DRS method was found to be better for solid materials considering the scattering component. The UV-Vis characterization results show that an increase in annealing temperature causes a decrease in Eg. For example the values ​​at 700°C, 750°C and 800°C are 3.5 ± 0.01 eV; 3.3±0.01 eV and 3.2±0.01 eV. The decrease in Eg is related to the diffusion of Barium Titanate (BaTiO3) ions into the Barium Zirconium Titanate (BZT) lattice forming a new sub-gap which in turn gives BT-BZT the ability to absorb lower light. Lower light absorption means more capable optics for multilayer systems.

Formaldehyde Cross-Linked Chitosan as Silver-Nanoparticles Stabiliser For Cr(VI) Ion Sensor Application

We report for the first time a technique in the detection of chromium(VI) [Cr(VI)] ions using ultraviolet-visible (UV-Vis) spectrophotometer that involves silver nanoparticles (AgNPs) capped with formaldehyde-chitosan as the sensor. Here, chitosan cross-linked with formaldehyde produced an extra stability from the aspect of signal stability of the sensor. This study aimed to synthesise and characterise formaldehydechitosan stabilised AgNPs (formaldehyde-chitosan@AgNPs) and apply them as Cr(VI) ion sensors. The stability and linearity of the signal of the formaldehyde-chitosan@ AgNPs were compared with the signal of AgNPs according to their ability as Cr(VI) ion sensors based on the UV-Vis spectroscopy. The AgNPs were synthesised by the chemical reduction method using 1% sodium citrate (10:1). Furthermore, 3.3% chitosan was added, which had been cross-linked with 2.5% formaldehyde in a ratio of 1:1 (v:v). The characterisation results showed that the synthesised materials have a peak absorption at a wavelength of 416 nm and have functional groups of -OH and -C=O as the characteristics of chitosan and formaldehyde. The formaldehyde-chitosan@AgNPs had square or rectangular structures with a size distribution of less than 1000 nm. The formaldehydechitosan@AgNPs produced a more stable signal and had better linearity than AgNPs at a wavelength of 490 nm. Moreover, formaldehyde-chitosan@AgNPs had a precision value of 0.15% and a linearity level of 0.9914 in the concentration range of 1 ppm–100 ppm, with limit of detection (LOD) and limit of quantisation (LOQ) values of 0.329 ppm and 0.751 ppm, respectively.

Green Synthesis and Photocatalytic Dye Degradation Activity of CuO Nanoparticles

The degradation of dyes is a difficult task due to their persistent and stable nature; therefore, developing materials with desirable properties to degrade dyes is an important area of research. In the present study, we propose a simple, one-pot mechanochemical approach to synthesize CuO nanoparticles (NPs) using the leaf extract of Seriphidium oliverianum, as a reducing and stabilizing agent. The CuO NPs were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and Fourier-transform infrared spectroscopy (FTIR). The photocatalytic activity of CuO NPs was monitored using ultraviolet-visible (UV-Vis) spectroscopy. The CuO NPs exhibited high potential for the degradation of water-soluble industrial dyes. The degradation rates for methyl green (MG) and methyl orange (MO) were 65.231% ± 0.242 and 65.078% ± 0.392, respectively. Bio-mechanochemically synthesized CuO NPs proved to be good candidates for efficiently removing dyes from water.

MODIFICATION OF PROTON PUMP MEMBRANE USING POLYVINYLPYRROLIDONE (PVP) FOR POTENTIAL TOTAL ALKALINITY SENSING

Total alkalinity is one of the important parameter in the regulation of seawater carbonate chemistry system to determine the capacity of water to neutralize acid. In this paper, a new proton pump membrane was successfully modified using polyvinylpyrrolidone (PVP) as a supporting material due to its excellent chemical properties. The surface morphology of the membrane was thoroughly studied using Scanning Electron Microscope (SEM), which showed the presence of pore structure, ascribed to the presence of low molecular weight of PVP. The absorption of membrane was studied using Ultraviolet-Visible (UV-Vis) spectrophotometer, where the peak appeared at 539 nm-1. The functional group of the modified membrane was analyzed using Fourier Transform Infrared Spectroscopy (FTIR), and the spectra showed almost similar between modified membrane with PVP and without PVP. The electrochemical behaviour of the membrane was evaluated by cyclic voltammetry (CV) using gold (Au) electrode and the resulting voltammogram showed that the modified membrane with PVP has higher current reading compared to the membrane without PVP, indicating that there is redox reaction occured during the immobilization. The condition and perfomance of modified proton pump membrane with PVP was compared and analyzed.

Functionalization of Gold Nanostars with Melamine for Colorimetric Detection of Uric Acid.

Gold nanostars (AuNSs) are synthesized using a seed-mediated growth method. The synthesized AuNSs solution is stable and shows a localized surface plasmon resonance (LSPR) band in the visible range, which is confirmed using ultraviolet-visible (UV-Vis) spectroscopy. Furthermore, the as-synthesized AuNSs were functionalized with melamine and used as a sensor for the colorimetric detection of uric acid (UA). The detection mechanism could be assessed through various analytical techniques such as UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS), zeta potential, field emission scanning electron microscopy (FE-SEM), and transmission electron microscopic techniques. These methods exhibited a good linear regression between the absorption ratio of LSPR band of melamine-AuNSs and the concentration of UA (0-120 µM), with the detection limit of 8.50 nm. As a result, UA was quantitatively detected in biofluids by using melamine-AuNSs as a colorimetric sensor, revealing melamine-AuNSs-based colorimetric approach which could be used as a simple platform for UA assay in biofluids.

Nanoporous carbon from waste egg shells modified with copper-nanoparticles – An Efficient material for removal of microbial contaminants from polluted water

The paper examines the efficiency of nanoporous carbon modified with copper nanoparticles (nC@CuNPs) for the removal of microbial contaminants from polluted waters. The modified material was prepared by wet impregnation of the unmodified carbon material in a solution of as-prepared Cu-nanoparticles. The materials were characterized by UV-Visible Spectroscopy, Fourier Transform-Infrared (FTIR) Spectroscopy, and Thermogravimetric Analysis. The materials were then investigated for their ability to remove copper and lead using Atomic Absorption Spectroscopy (AAS), methylene blue using Ultraviolet-Visible (UV-Vis) Spectroscopy and microbial contaminants from simulated polluted water. The results showed that in addition to retaining its heavy metals (Cu and Pb), and methylene blue removal capacity, the modified material, nC@CuNPs was efficient in removing microbial contaminants (E. coli and Salmonella) from the polluted water. The study provides an avenue for the provision of easy access to a range of such water purification materials to the increasing world population and contributes towards meeting the United Nationals Sustainable Development Goals (UN SDGs).

Colorimetric and handheld pH meter dual-signal readout platform for E. coli detection based on a cascade reaction.

Adual-signal readout has been designeddetecting platform based on a cascade reaction for Escherichia coli (E. coli) detection by using colorimetric approach and a handheld pH meter. The immunoreaction was conducted using polydopamine@copper ferrite-Ag nanoparticles (PDA@CuFe2O4-Ag NP) and a glucose oxidase (GOD)-conjugated graphene oxide-gold nanosheet composite (GOD-GO/Au NS) to synthesize a sandwich complex mode between targets. Together with the formation of immune complexes, the GOD-GO/Au NS can catalyze glucose to produce gluconic acid and hydrogen peroxide (H2O2). The gluconic acid produced altered the pH of the detection solution. Since the PDA@CuFe2O4-Ag NP have good peroxidase-like activity, they can catalyze the oxidation of TMB to the blue product oxTMB once H2O2 is produced in the reaction system, and the absorbance change of oxTMB at 652nm can be recorded using ultraviolet-visible (UV-Vis) spectroscopy. Interestingly, the PDA@CuFe2O4-Ag NP composites can consume the generated H2O2, and can create a reaction cycle that promotes glucose oxidation. Under optimal conditions, the proposed dual-channel signal platform is proportional to the logarithm of the E. coli concentration within a range of 102-107cfumL-1. Additionally, the devised approach was successfully used to detect E. coli at the required levels in real samples. This dual-mode detection method notably enhances the accuracy and diversity of detection, and curbs the false negative and positive rates.

Study of optical properties of guar gum electrolytes

Guar gum is a naturally occurring non-ionic polysaccharide that can be found in Cyamopsis tetragonolobus' endosperm. Guar gum-based solid-state electrolytes synthesized by solution casting and doped with ZnSO4·7H2O salt in various %W/W ratios. These guar gum electrolytes’ optical characteristics have been studied by using Ultraviolet–visible (UV-V) spectrophotometry within the wavelength range200-900 nm. From optical absorption spectra, the cut-off wavelength was calculated and it has been decreasing (305.49 → 263.9 nm) with increasing salt weight proportion ratios from 10 to 30 wt%. The Urbach energy of guar gum and salt with guar gum electrolytes has been calculated, and non-linear fluctuation was seen in the present study. The transmittance increases with the increasing salt weight proportion (10-30 wt%). The rapid increment of transmittance has been observed below and above the visible region. The non-linear variation has been found for the extinction coefficient of the salt-dopants electrolyte samples. The refractive index has been calculated for all prepared gum electrolytes. The highest refractive index value (1.752) was obtained for pure guar gum, and with the addition of salt, the refractive index decreased. The optical conductivity decreases with the addition of salt to the pure guar gum. The optical band gap energy (direct allowed bandgap, indirect allowed bandgap, direct forbidden bandgap, indirect forbidden bandgap) has been calculated for all pure guar gum and its electrolytes. The optical complex dielectric characteristics (constant, loss) have been examined. The optical dielectric loss edge has been determined for guar gum electrolytes.

Features of structure and optical properties GO and a GO/PVA composite subjected to gamma irradiation.

In this study, a modified Hummers' method was employed to prepare graphene oxide (GO), which was then mixed with polyvinyl alcohol (PVA) polymer at varying weight concentrations (1 wt% and 5 wt%). The prepared GO and GO/PVA nanocomposite films were subjected to gamma (γ) radiation at different doses (10, 500, and 1500 kGy) to analyze the effects on their structure and optical properties. The structural changes in the nanocomposites were analyzed using X-ray diffraction (XRD), allowing for the determination of any alterations resulting from exposure to radiation at different doses. Furthermore, elemental analysis was conducted using an energy-dispersive spectrometer (EDS) to gain insights into the elemental composition of the samples. The optical properties of the samples were investigated using ultraviolet-visible (UV-Vis), Fourier-transform infrared (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM). These analysis methods provided valuable information regarding any changes induced by gamma radiation. Notably, in the study, the decomposition and oxidation of residual graphite were observed under the influence of γ radiation. One noteworthy finding was the decrease in the band gap value of the samples with increasing gamma radiation. This observation indicates that the radiation exposure influenced the electronic properties of the nanocomposites, leading to changes in their optical behavior. The Raman spectra clearly showed that the strength of the G and D bands dropped at low doses and reached a maximum at higher doses. FTIR intensity varies with radiation, indicating the separation of oxygenated groups during exposure. The SEM images revealed that as the radiation dose increases, the disintegration of GO on the polymer's surface happens, and at the greatest dose, the distribution of GO and PVA in the pores occurs due to the heating action of radiation.

Determination of the antagonistic efficacy of silver nanoparticles against two major strains of Mycobacterium tuberculosis

Tuberculosis (TB) is considered one of the most prominent diseases across the globe. This present study aims to inspect the impact of silver nanoparticles (AgNP) against Mycobacterium tuberculosis, which is the causative vector of TB. The efficacy of the AgNP was conducted based on the minimum inhibitory concentration (MIC) of the AgNPs through microplate Alamar blue assay. The preparation of the AgNPs involved chemical synthesis. The state and the size of the AgNPs were determined and confirmed by using ultraviolet-visible (UV-Vis) absorption spectroscopy, X-ray diffraction (XRD) spectroscopy, and Transmission electron microscopy (TEM). This study evaluated two strains: Mycobacterium tuberculosis H37Rv and Mycobacterium bovis. In addition, another multiple drug-resistant Mycobacterium tuberculosis strain was also considered in this study, along with the clinically obtained isolates from Mycobacterium tuberculosis H37Rv and Mycobacterium tuberculosis bovis. The synthesized nanoparticles were found to be tetrahedral in shape with an average particle size of 45±3 nanometre (nm). The obtained results indicated that the proliferation of all the strains (two reference strains and one MDR strain) was resisted by the action of the synthesized AgNPs. The MIC of the MDR strain was noted within the range of 2-12 µg/ml, whereas the MIC for the Mycobacterium tuberculosis H37Rv and Mycobacterium bovis was noted in the range of 2-14 and 3-30 µg/ml, respectively. Accordingly, this study proposed a novel approach to combat tuberculosis, which is considered a global threat to humankind, indicating the present study's novelty.

How Chemometrics Revives the UV-Vis Spectroscopy Applications as an Analytical Sensor for Spectralprint (Nontargeted) Analysis

In recent years, methodologies based on spectral analysis, using ultraviolet–visible (UV-Vis) radiation, have experienced an amazing development and have been widely applied in various fields such as agricultural, food, pharmaceutical, and environmental sciences. This straightforward technique has re-emerged with novel and challenging proposals to solve, in a direct and fast way, a wide variety of problems. These reaches would not have been possible without the essential support of chemometrics. In this sense, under the general background of the development in data and computer science, and other technologies, the emergence of innovative ideas, approaches, and strategies endows UV-Vis spectroscopy with a new vitality as an analytical sensor with the capability of significantly improving both the robustness and accuracy of results. This review presents modern UV-Vis spectral analysis, which is on the rise, associated with comprehensive chemometric methods that have become known in the last six years, especially from the perspective of practicability, including spectral preprocessing, wavelength (variable) selection, data dimension reduction, quantitative calibration, pattern recognition, and multispectral data fusion. Most importantly, it will foresee future trends of UV-Vis spectroscopy as an analytical sensor for a spectralprint (nontargeted) analysis.