Using Ultraviolet-visible Spectroscopy Research Articles

Photophysical Properties of Sinapic Acid and Ferulic Acid and Their Binding Mechanism with Caffeine.

Sinapic acid (SA) and ferulic acid (FA) are bioactive compounds used in the food, pharmaceutical, and cosmetic industries due to their antioxidant properties. In this work, we studied the photophysical properties of SA and FA in different solvents and concentrations and their interactions with caffeine (CF), using ultraviolet-visible (UV-Vis), fluorescence spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The findings show that the quantum yield, fluorescence lifetime, radiative decay rates, and non-radiative decay rates of SA and FA are influenced by the concentrations and solvent polarity. The interaction between SA and FA with CF was also studied using UV-Vis and fluorescence spectroscopy. The results indicate that the CF quenched the fluorescence intensity of SA and FA by static quenching due to the formation of a non-fluorescent complex. The van't Hoff equation suggests that the van der Waals forces and hydrogen bonds force were responsible for the interaction between SA and CF, as indicated by a negative change in enthalpy ( < 0) and a negative change in entropy ( < 0). On the other hand, the interaction between FA and CF was primarily controlled by electrostatic force, as indicated by a negative change in enthalpy ( < 0) and a positive change in entropy ( > 0). The negative change in Gibbs free energy ( ) indicates that both compounds underwent a spontaneous binding process.

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.

First Report of green Synthesis of Copper Oxide Nanoparticles from Brassica Tournefortii Leaves Extract and Their Antibacterial Activity

In the present study, copper oxide nanoparticles (CuO NPs) were synthesized using a eco-friendly technique and evaluated their antibacterial activity. At the first time, Brassica tournefortii leaves extract mediated copper oxide-based nanoparticles which prepared by a bio-reduction method using an aqueous Brassica tournefortii leaves extract as both a reducing and stabilizing agent. Copper oxide nanoparticles were characterized by using ultraviolet-visible spectroscopy (UV-VIS), Fourier transform-infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The synthesized CuO nanoparticles were also evaluated for their antibacterial activity against gram-positive (Staphylococcus aureus and Streptococcus spp) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains. UV-Vis and FT-IR

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.

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.

Correlating solvation-adsorption phenomena of some styrylpyridinium dyes on SDS modified silica surface in organic media

Sodium dodecyl sulfate modified silica (SDSMS) surface has been used to study the adsorption of some cationic styrylpyridinium dyes from organic solvent media using ultraviolet-visible (UV-Vis) spectrophotometric technique. The modifications of silica surface and subsequent modification through adsorption of dye molecules on the surface have been characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy and zeta potential measurements. Kinetics of adsorption and consequent thermodynamic parameters have been studied and discussed. The isotherm modeling, choice of solvents from sedimentation analysis, and other common adsorption related parameters such as amount of adsorbent dosage, contact time, adsorption efficiencies have been reported. The influences of solvents and the substituents present on the dye molecules, on the rate of adsorption have been discussed. A pictorial model of adsorption process has been suggested based on the experimental results.

Cerium Oxide Nanorods Synthesized by Dalbergia sissoo Extract for Antioxidant, Cytotoxicity, and Photocatalytic Applications

In this study, cerium oxide nanorods (CeO2-NRs) were synthesized by using the phytochemicals present in the Dalbergia sissoo extract. The physiochemical characteristics of the as-prepared CeO2-NRs were investigated by using ultraviolet-visible spectroscopy (UV-VIS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD). The SEM and UV-VIS analyses revealed that the acquired nanomaterials possessed a rod-like morphology while the XRD results further confirmed that the synthesized NRs exhibited a cubic crystal lattice system. The antioxidant capacity of the synthesized CeO2-NRs was investigated by using several in vitro biochemical assays. It was observed that the synthesized NRs exhibited better antioxidant potential in comparison to the industrial antioxidant of the butylated hydroxyanisole (BHA) in 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The biochemical assays, including lipid peroxidation (LPO), total antioxidant capacity (TAC), and catalase activity (CAT), were also performed in the human lymphocytes incubated with the CeO2-NRs to investigate the impact of the NRs on these oxidative biomarkers. Enhanced reductive capabilities were observed in all the assays, revealing that the NRs possess excellent antioxidant properties. Moreover, the cytotoxic potential of the CeO2-NRs was also investigated with the MTT assay. The CeO2-NRs were found to effectively kill off the cancerous cells (MCF-7 human breast cancer cell line), further indicating that the synthesized NRs exhibit anticancer potential as well. One of the major applications studied for the prepared CeO2-NRs was performing the statistical optimization of the photocatalytic degradation reaction of the methyl orange (MO) dye. The reaction was optimized by using the technique of response surface methodology (RSM). This advanced approach facilitates the development of the predictive model on the basis of central composite design (CCD) for this degradation reaction. The maximum degradation of 99.31% was achieved at the experimental optimized conditions, which corresponded rather well with the predicted percentage degradation values of 99.58%. These results indicate that the developed predictive model can effectively explain the performed experimental reaction. To conclude, the CeO2-NRs exhibited excellent results for multiple applications.

Analysis between Linagliptin and Azithromycin: In vitro and In vivo Interaction Study.

Linagliptin is prescribed as a dipeptidyl peptidase-4 (DPP-4) inhibitor. Azithromycin is specified as an antibiotic that binds with 23s rRNA of the 50s ribosomal subunit, obstructing the microbial protein synthesis. Our study focuses on the drug-drug interactions of these drugs. The purpose of the study is to understand the bioavailability and physicochemical approaches of Linagliptin and Azithromycin interaction mediated through the strength and nature of the complexation. TheIn vitro assessment of drug interaction was conducted using Ultraviolet-visible spectroscopy (UV/VIS), Ultra-Performance Liquid Chromatography (UPLC), Fourier transform infrared spectroscopy (FT-IR), and Differential scanning calorimetry (DSC), while the Oral Glucose Tolerance Test (OGTT) was performed for theIn vivo assessment of drug interaction in a mouse model. Mild variation in interaction was observed at different pH values at a specific temperature by Job's and Ardon's equations. In UPLC, the drug mixture assessment showed that the area of Linagliptin was 2013793, and the area of Azithromycin was 54631 in 50 mg/l. The height of Linagliptin in the drug mixture was 579234, and that of Azithromycin was 11442. For Azithromycin, the wavelength of 731.02 cm-1, 993.34 cm-1, 1379.10 cm-1, and 1718.58 cm-1 decreased in the mixture. Also, for Linagliptin, the wavelength 1363.67 cm-1, 1473.62 cm-1, and 1718.58 cm-1 decreased in the drug mixture. The melting endotherm was 125.55°C, melting normalized energy was -3.0 W/mg, and 225.75°C with melting normalized energy of -5.5 W/mg of the drug mixture as indicated by DSC. In the OGTT test, the blood glucose level of Linagliptin decreased in the drug mixture by 13.58 % and 57.25%. Hence, the concomitant administration of Linagliptin and Azithromycin simultaneously might reduce the therapeutic effect of the drug complex.

Anti-dengue activity of super critical extract and isolated oleanolic acid of Leucas cephalotes using in vitro and in silico approach

BackgroundsLeucas cephalotes is a common ethnomedicinal plant widely used by traditional healers for the treatment of Malaria and other types of fever. Oleanolic acid and its derivatives have been reported for various types of pharmacological activities, such as anti-inflammatory, antioxidant, anticancer, hepatoprotective, anti-HIV and anti-HCV activity.MethodsL.cephalotes plant extracts were prepared by supercritical fluid extraction (SFE) method and oleanolic acid was isolated by preparatory thin-layer chromatography. The compound was identified and characterize by using ultraviolet-visible spectroscopy (UV-VIS), Fourier transform infra-Red spectroscopy (FT-IR) and high-performance thin-layer chromatography (HPTLC). The structure of the compound was elucidated by proton nuclear magnetic resonance (1HNMR) and carbon nuclear magnetic resonance (1CNMR) and the purity checked by differential scanning calorimetry (DSC). The MTT assay was used to determine the toxicity of plant extract and oleanolic acid using a microplate reader at 595 nm. The anti-dengue activity of plant extract and oleanolic acid was tested in vitro and in silico using real-time RT-PCR.ResultsThe optimum yield of the extract was obtained at 40 °C temperature and 15Mpa pressure. The maximum non-toxic dose (MNTD) of plant extract and oleanolic acid were found as 46.87 μg/ml and 93.75 μg/ml, respectively in C6/36 cell lines. UV spectrophotometer curve of the isolated compound was overlapped with standard oleanolic acid at 232 nm. Superimposed FT-IR structure of the isolated compound was indicated the same spectra at 3433, 2939, 2871, 1690, 1500,1463, 1387, 1250, 1209, 1137 and 656 position as per marker compound. HPTLC analysis showed the retention factor of L. cephalotes extract was 0.19 + 0.06 as similar to the standard oleanolic acid chromatogram. The NMR structure of the isolated compound was identified as similar to the marker oleanolic acid structure. DSC analysis revealed the purity of isolated oleanolic acid was 98.27% with a melting point of 311.16 °C. Real-time RT PCR results revealed that L. cephalotes supercritical extract and isolated oleanolic acid showed 100 and 99.17% inhibition against the dengue − 2 virus when treated with MNTD value of plant extract (46.87 μg/ml) and the test compound (93.75 μg/ml), respectively. The molecular study demonstrated the binding energy of oleanolic acid with NS1and NS5 (non-structural protein) were − 9.42 & -8.32Kcal/mol, respectively.ConclusionsThe SFE extract L. cephalotes and its active compound, oleanolic acid inhibiting the activity of dengue-2 serotype in the in vitro and in silico assays. Thus, the L.cephalotes plant could be an excellent source for drug design for the treatment of dengue infection.

The Annealing Impact on Properties of CN- 85 Polymer NTD

Samples of cellulose nitrate polymer (CN-85) were annealed at 100 °C, 120 °C, and 140 °C for 15 min before and after irradiation with alpha particles emitted from a241Am source. Irradiation was performed at room temperature for 5 min. The changes in the optical and structural properties of CN-85 NTD, due to annealing and irradiation, were studied by using ultraviolet–visible spectroscopy (UV-VIS), and Fourier transform infrared spectroscopy (FTIR). Direct and indirect energy gap values, the number of carbon atoms, carbon clusters, and Urbach's energy values were determined. The UV-VIS analysis showed a shift in the absorption edge of the CN-85 polymer toward long wavelengths. The FTIR results revealed the changes in some bonds and the structural decomposition of CN-85 due to irradiation. The direct band gap energy was slightly decreased from 4.13 eV to 4.09 eV when the pristine samples were heated to 140 °C and irradiated. The indirect band gap energy was decreased from 3.9 eV to 3.8 eV under the same conditions. The Urbach's energy values showed a fluctuating rise with increasing annealing temperature for the irradiated and heated samples. When the pristine samples irradiated and heated, the band gap energy is reduced from 4.13 eV to 4.06 eV and from 3.90 eV to 3.84 eV for the direct and indirect transition, respectively. In conclusion, this technique showed promising benefits for a wide range of applications such as optoelectronics and microelectronic devices.

Synthesis of biogenic silver nanoparticles from polyphenolic Brassica nigra and their potential antifungal, antibacterial, antioxidant, and anticancer activities

Green synthesis of silver nanoparticles (AgNPs) has consistently revolutionised the field of nanotechnology, and bio-based AgNPs have emerged as efficient therapeutic tools in biomedical science. The present work focused on the synthesis and characterisation of eco-friendly AgNPs from Brassica nigra (BN), and the evaluation of antibacterial, antifungal, anticancer, and antioxidant activity in the MCF-7 human breast cancer cells. The characteristics of BN-AgNPs was studied using ultraviolet-visible (UV-Vis) spectroscopy, particle size analysis, electro kinetic/zeta potential analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Elemental composition was determined using energy-dispersive spectroscopy (EDX). UV-Vis spectroscopy confirmed the formation of BN-AgNPs. The TEM micrographs showed that BN-AgNPs were spherical and well distributed in the solution without aggregation. Anticancer activity was determined at different BN-AgNPs concentrations in the MCF-7 cell line with the maximum cytotoxic effect observed at 100 μg/mL. The synthesised BN-AgNPs demonstrated strong antifungal and antibacterial activities against all microbial strains examined with varying degrees. The scavenging action on free radicals by BN-AgNPs showed strong antioxidant efficiency with DPPH, nitric oxide, superoxide, and hydroxyl radicals at different concentrations. The green synthesis of BN-AgNPs is comparatively simple, eco-friendly, and safer than conventional methods; and the observed anticancer activity is suggestive of the role of biogenic BN-AgNPs as potential therapeutic agents for cancer therapy.

Green synthesis of silver nanoparticles using Phyllanthus amarus Seeds and their antibacterial activity assessment

Background: Green synthesis of nanoparticles has been gaining popularity due to its advantages over chemical synthesis. In the present study, silver nanoparticles (AgNPs) were synthesized by using an aqueous solution of Phyllanthus amarus leaves extract as a reducing agent. The synthesized nanoparticles were characterized using the spectroscopic techniques. The Fourier-transform infrared (FTIR) study confirmed that the seed extract also stabilized the surface of the AgNPs by acting as a capping agent. Moreover, the antibacterial activity of the plant NPs was also assessed. The synthesized nanoparticles as well as P. amarus plant extract were separately tested to examine their antibacterial activities. The activities were tested against various microorganisms, including Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, and Staphylococcus aureus. The main aim of the present study is to evaluate the green synthesis of nanoparticles using P. amarus seeds and their antibacterial activity assessment. Method: Collection and preparation of seed extract, synthesis of AgNPs, characterization of AgNPs using ultraviolet-visible (UV-Vis) absorbance spectroscopy and Fourier transforms infrared spectroscopy, determination of antibacterial activity using pathogens. All in vitro assay data signify the mean ± standard deviation of triplicates was calculated by using the MS word document. Results: The reduction of silver nitrate using the plant leaf extract was viewed by the color change in the reaction solutions. The maximum absorbance peak was seen at 400 nm for P. amarus seed extract using UV-Vis spectroscopy and FTIR measurements were carried out for the AgNPs synthesized by the plant extracts. The extracts of P. amarus seeds showed potent antimicrobial activity against Gram-positive and negative bacteria. Conclusions: The biosynthesized AgNPs using P. amarus seed extract proved to be excellent agent against pathogens. The present study showed a simple, rapid, and economical route to synthesize AgNPs. The use of P. amarus has the added advantage that this seed can be used by nanotechnology processing industries.

Identification and characterization of new potent inhibitors of dengue virus NS5 proteinase from Andrographis paniculata supercritical extracts on in animal cell culture and in silico approaches

Ethnopharmacological relevanceAbout 2.5 billion peoples are at risk of dengue virus and the majority of people, use traditional plant-based medicines to combat dengue. The whole plant of Andrographis paniculata used traditionally over past decades for health promotion. Andrographolide isolated from Andrographis paniculata is used as natural remedy for the treatment of various diseases in different parts of the world. Andrographolide has been reported to have antiviral activity against hepatitis B virus, hepatitis C virus, herpes simplex virus, influenza virus, chikungunya virus, dengue virus 2 and 4. Aim of the studyThe aim of the present study to isolate the andrographolide from the A. paniculata by supercritical fluid extraction technique and to characterize the isolated compound along with it anti-dengue activity against DENV-2 in vitro and in silico methods. Materials and methodsSupercritical extraction condition for A. paniculata was standardised to isolate andrographolide compound at definite temperature and pressure on the basis of previous study. The andrographolide was identified by using Ultraviolet–Visible Spectroscopy (UV-VIS), Fourier-Transform Infrared Spectroscopy (FT-IR) and High Performance Thin Layer Chromatography (HPTLC) and Proton Nuclear Magnetic Resonance (1HNMR). The maximum non-toxic dose of isolated andrographolide was detected by MTT assay using a micro plate reader at 595 nm. One hundred (100) copies/ml of the DENV-2 virus was used for antiviral assay in C6/36 cells lines and inhibition of virus due to andrographolide was determined by real-time PCR assay. The purity of isolated andrographolide was determined by Differential Scanning Calorimetry (DSC). The dengue NS5 receptor protein was docked with andrographolide and evaluated on the basis of the total energy and binding affinity score by Auto Dock (V4.2.6) software. ResultsAndrographolide, a diterpene lactone was isolated from the A. paniculata supercritical extract at 40 °C temperature and 15 Mpa pressure. UV spectrophotometer analysis revealed that the curve of andrographolide plant extract was overlapped with reference compound at 228 nm and the similar bands were detected from FT-IR spectroscopy analysis at 3315, 2917, 2849, 1673, 1462 and 1454 cm−1 in isolated and standard andrographolide. HPTLC analysis shows the retention factor (Rf) of A. paniculata extract at 0.74 ± 0.06 as similar to standard andrographolide Rf values. The purity of isolated andrographolide was 99.76%. The maximum non-toxic dose of isolated andrographolide was found as 15.62 μg/ml on the C6/36 cell line calculated by using MTT assay. The andrographolide showed the 97.23% anti-dengue activity against the dengue-2 virus in C6/36 cell lines. Results of molecular docking showed that the interaction between andrographolide and NS5 of dengue protein with the maximum binding energy as −7.35 kcal/mol. ConclusionsIt is concluded that isolated andrographolide from the A. paniculata possess anti-dengue activity against dengue-2 virus as revealed from in vitro and in silico method. Due to lack of the vaccine and anti-viral agents, andrographolide extracted from A. paniculata play a major role to inhibit the dengue replication. Hence, it could be a source for drug design and help to reduce the dengue infection.

Experimental investigation of tribological effect on vegetable oil with CuO nanoparticles and ZDDP additives

PurposeThis paper aims to report the friction and wear characteristics of refined soybean oil (RSBO) blended with copper oxide (CuO) nanoparticles and zinc dialkyldithiophosphate (ZDDP) as additives.Design/methodology/approachFour different concentrations 0.04, 0.05, 0.1 and 0.2 Wt.% of CuO nanoparticles were added with ZDDP in RSBO. The friction and wear characteristics of lubricants have been investigated on a pin-on-disc tribotester under loads of 120 and 180 N, with rotating speeds of 1,200 and 1,500 rpm in half hour of operating time. The dispersion stability of CuO nanoparticles has been analyzed using ultraviolet visible (UV-Vis) spectroscopy. The wearout surface of pins has been examined by using a scanning electron microscope.FindingsThe results revealed that there is a reduction in the friction and wear by the addition of CuO nanoparticles and ZDDP in RSBO. Coefficient of friction increases at a high sliding speed for RSBO with ZDDP. From UV-Vis spectroscopy, it is observed that 100 ml of oleic acid surfactant per gram of CuO nanoparticles has stable dispersion in RSBO.Originality/valueThe addition of ZDDP and CuO nanoparticles in RSBO is more efficient to reduce the friction and wear in comparison to base oil. The optimum concentration of CuO nanoparticles in RSBO is 0.05 Wt.%.

IN VITRO CYTOTOXICITY OF BIOSYNTHESIZED GOLD NANOPARTICLES FROM SHELLS OF PISTACIA VERA L

Objective: To synthesize the gold nanoparticles by a biological method using the extract obtained from the shells of Pistacia vera (P. vera) and to study its effective role in the anticancer activity.Methods: The synthesis of gold nanoparticles using the extract obtained from the shells of Pistacia vera was confirmed by the color change and substantiating the same using ultraviolet (UV) visible spectroscopy. The size and the shape of the particles were studied using field emission scanning electron microscopy (FESEM). The stability of the nanoparticles was assessed by using the UV visible spectroscopy and Fourier-transform infrared spectroscopy (FTIR). The anticancer activity of the gold nanoparticles on the cancer cell lines was studied on PA1 ovarian cancer cell lines using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Nature of cell death was analyzed using the fluorescence microscopy.Results: The ruby red color confirmed the formation of gold nanoparticles and it was substantiated by the absorption peak at 543.2 nm in the UV visible spectroscopy. The gold nanoparticles synthesized from the Pistacia vera shell showed the spherical shape and were in the size of around 10-40 nm when analyzed with FESEM. The different functional groups were indicated in the FTIR spectra which were consisting of phenol, alcohol, alkenes and aromatics.Conclusion: The synthesis of the gold nanoparticle using the extract obtained from the shells of Pistacia vera has effective anticancer activity.

RETRACTED: Microwave-assisted synthesis and characterization of WOx nanostructures for gas sensor application

Abstract Tungsten oxide (WO x ) nanoparticles were synthesized by a facile and eco-friendly microwave-assisted hydrothermal method without need for using any surfactant. A thorough investigation was performed in order to elucidate the effects of microwave irradiation time (10, 20 and 30 min) on the structural, morphological and optical properties of the as-prepared WO x . Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) of the samples revealed the presence of irregular nanosized particles containing some well-structured rod shape particles. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that these nanoparticles are crystallines with mean crystalline size of about 16 nm exhibiting both monoclinic and orthorhombic WO x crystal structures. The optical properties were investigated by using ultraviolet visible spectroscopy (UV-VIS) and photoluminescence (PL). A blue-shifted optical absorption spectrum with an enhanced defects emission was observed when it was compared to bulk spectrum of WO 3 . Thermal-aged WO x nanoparticles at mild temperature (350 °C) were also used to fabricate conductometric gas sensors Gas sensing tests showed excellent performance towards ethanol monitoring for each synthesized material. In particular, the highest sensitivity was obtained for the sensor based on WO x synthesized by 10 min irradiation time (S10). At the optimal operating temperature of 300 °C, the S10 sensor showed a response R a /R g = 8.5 towards 100 ppm ethanol with fast response time of 10 s, in addition to an excellent selectivity against common interfering gases.

Synthesis of Titanium Dioxide Nanoparticles Using Echinacea purpurea Herba.

Nowadays green synthesis of metal nanoparticles is a developing area of research. In this study, titanium dioxide nanoparticles were biosynthesized using an aqueous solution of Echinacea purpurea herba extract as a bioreductant. This is novel and interesting method for synthesis of TiO2 nanoparticles. The prepared titanium dioxide nanoparticles were characterized using ultraviolet-visible spectroscopy (UV-VIS), transmission electron microscopy (SEM), total reflection X-Ray fluorescence analysis (TXRF) and Fourier-transform infrared spectroscopy (FTIR). The size of TiO2 nanoparticles was found to be in the range of 120 nm. Moreover, the alkaline reaction of the solution (pH = 8) resulted in the increase in absorbance (280 nm), which facilitates the growth of the number of TiO2 nanoparticles in the studied solution. Also, synthesis of TiO2 nanoparticles using green resources like Echinacea purpurea herba is a better alternative to chemical synthesis, since this green synthesis is pollutant-free and eco-friendly.

Preparation and Characterization of Nanostructured CuO Thin Films using Sol-gel Dip Coating

Nanostructured CuO thin films were deposited onto quartz substrates by sol-gel dip coating technique. The precursor solution was prepared by dissolving copper acetate powder into isopropanol with molarity of 0.25M. Preheating and annealing temperature were fixed at 250°C and 600°C respectively. This study focused on various film thicknesses by varying the frequent number of deposited layers. The effect of thickness on electrical, surface morphology and optical properties of CuO thin film were studied. The surface morphology was examined using field emission scanning electron microscopy (FE-SEM), surface profiler for thickness measurement, optical properties of CuO thin film were characterized by using ultraviolet- visible spectroscopy (UV-VIS) for transmittance and absorbance, and the electrical property was examined by using two point probes method. The films were found to be denser at higher film thickness due to lesser porous observed on the surface. The thickness of these CuO thin films varied from 87.14 – 253.58 nm and the direct band gap energy was observed in between 1.9 to 2.35 eV. Lowest resistivity was found for sample with a thickness of 253.58 nm.

Effect of Temperature on the Optical and Morphological Properties of Zinc Oxide Thin Films Prepared by RF Magnetron Sputtering

This investigation deals with the effect of temperature on the optical and morphological properties of Zinc Oxide thin films prepared by radio-Frequency (RF) magnetron sputtering technique. In the present work, zinc oxide (ZnO) thin films have been deposited on glass substrates from 50°C to 300°C by radio frequency magnetron sputtering. The effects of deposition temperature on the crystallization behaviour and optical properties of the films have been studied. The thin films were characterized using Ultraviolet Visible Spectroscopy (UV-VIS), Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction Analysis (XRD). From the UV-VIS testing, the average transmission percentage of the films is between 80-95% for all deposition temperatures meanwhile the energy gap of ZnO thin films varies from 3.26 eV to 3.35 eV which is not much different from the theoretical value. Also, the grain size is getting smaller from 3.886nm, 3.216nm, 3.119nm and 3.079nm with respect to the increasing deposition temperature 50°C, 100°C, 200°C and 300°C respectively whereas the average grain size per intercept value is increasing. The patterns of the peak were about the same for all deposition temperature where the thin films have polycrystalline hexagonal wurtzite structure with the orientation perpendicular (002) to the substrate surface (c-axis orientation) at 34.5(2θ).

Analysis of pure tar substances (polycyclic aromatic hydrocarbons) in the gas stream using ultraviolet visible (UV-Vis) spectroscopy and multivariate curve resolution (MCR).

The analysis of tar, mostly characterized as polycyclic aromatic hydrocarbons (PAHs), describes a topic that has been researched for years. An online analysis of tar in the gas stream in particular is needed to characterize the tar conversion or formation in the biomass gasification process. The online analysis in the gas is carried out with ultraviolet-visible (UV-Vis) spectroscopy (190-720 nm). This online analysis is performed with a measuring cell developed by the Fraunhofer Institute for Chemical Technology (ICT). To this day, online tar measurements using UV-Vis spectroscopy have not been carried out in detail. Therefore, PAHs are analyzed as follows. The measurements are split into different steps. The first step to prove the online method is to vaporize single tar substances. These experiments show that a qualitative analysis of PAHs in the gas stream with the used measurement setup is possible. Furthermore, it is shown that the method provides very exact results, so that a differentiation of various PAHs is possible. The next step is to vaporize a PAH mixture. This step consists of vaporizing five pure substances almost simultaneously. The interpretation of the resulting data is made using a chemometric interpretation method, the multivariate curve resolution (MCR). The verification of the calculated results is the main aim of this experiment. It has been shown that the tar mixture can be analyzed qualitatively and quantitatively (in arbitrary units) in detail using the MCR. Finally it is the main goal of this paper to show the first steps in the applicability of the UV-Vis spectroscopy and the measurement setup on online tar analysis in view of characterizing the biomass gasification process. Due to that, the gasification plant (at the laboratory scale), developed and constructed by the Fraunhofer ICT, has been used to vaporize these substances. Using this gasification plant for the experiments enables the usage of the measurement setup also for the spectroscopic analysis of the tar formation during the biomass gasification.