FTIR Absorption Research Articles

Synthesis, characterization, and study of linear and non-linear optical properties of some newly thieno[2,3-b]thiophene analogs

Abstract Newly 3,4-Diaminothieno[2,3-b]thiophene derivatives were synthesized by attaching with different aromatic have rich electron. The resulted compounds have been investigated by FT-IR, NMR, elemental analysis, and optical absorption spectra. Comparison between these resulted compounds revealed oxoindolin-3-ylidene)amino)thieno[2,3-b]thiophene has the highest absorption peak intensity at ~ 696nm, thin films have been prepared by thermal evaporation technique and characterized by UV-Visible-NIR spectroscopy as well as the allied absorption, dielectric and dispersion parameters have been investigated and compared with other reported results. Obtained results indicated diethyl 3,4-bis(((E)-2-oxoindolin-3-ylidene)amino)thieno[2,3-b]thiophene-2,5-dicarboxylate and 3,4-bis(((E)-2-oxoindolin-3-ylidene)amino)thieno[2,3-b]thiophene-2,5-dicarbonitrile have manifested small band energy gap energy 1.95, 1.66 eV; respectively as a result of increasing conjugation and high absorption coefficient, make these compounds ideal for use in solar cell. The high nonlinear parameters such as refractive index and third-order nonlinear susceptibility of these organic compound thin films are significantly asymptotic compared with chalcogenide and oxide materials, making them suitable for nonlinear optical devices.

A novel gelatin/chitosan-based “sandwich” antibacterial nanofiber film loaded with perillaldehyde for the preservation of chilled chicken

Quality deterioration caused by microorganisms is a crucial problem in food industry. Herein, to enhance the antibacterial effect and extend the storage life of chilled chicken, a gelatin/chitosan (GC)-based “sandwich” nanofiber film was prepared by sandwiching GP2 (gelatin nanofibers loaded with 2 % (v/v) perillaldehyde) between two layers of GC nanofibers. The diameter of GP nanofibers was positively correlated with perillaldehyde concentration. However, the thermal stability of GP nanofibers was negatively correlated. The thermal degradation temperature (Tm) of GP2 was the lowest. Fortunately, GC nanofibers improved Tm of GP2 from 98.91 °C to 111.60 °C. Besides, FTIR absorption bands at 1636 and 1442 cm−1 indicated that perillaldehyde was successfully embedded. Moreover, poor water resistance of gelatin nanofibers was also improved. Specifically, benefiting from the synergy between perillaldehyde and chitosan, the shelf-life of chilled chicken was efficiently prolonged (over 10 days). Thus, this “sandwich” nanofiber film shows promise for food packaging.

Study of Natural Herbal Dyes Photodegradation Effect to Optical Properties for Dye-Sensitized Solar Cells

The stability of natural dyes for use in dye-sensitive solar cells is known from their photodegradation characteristics. Photodegradation effects using artificial light radiation on natural herbal dyes were investigated. Three natural herbal dyes, namely Fagraea acuminatissima, sappanwood, and kulit setong were used in this study. The stability of the natural herbal dyes under artificial light radiation was studied. The optical properties of the natural herbal dyes as indicators of their stability were characterized using FTIR and UV-VIS absorption. Stability testing of natural herbal dyes was conducted in a room with artificial lighting for 5 weeks. Observations of changes in their optical properties were performed weekly. It can be seen that all three natural herbal dyes contained anthocyanin. In addition to anthocyanin, Fagraea acuminatissima and sappanwood also contain chlorophyll. In contrast, the kulit setong contains beta-carotene in addition to anthocyanin. The degradation percentage showed that sappanwood degrade to all of its pigments. While an increase occurred in the chlorophyll peak of Fagraea acuminatissima and the beta-carotene peak of kulit setong. This clearly shows that Fagraea acuminatissima has the highest stability, and potentially increases the efficiency of solar cells.

One-pot synthesis of chiral cysteine-capped gold nanoparticles for use as vaccine adjuvants in mice

The influence of chirality on the biological activity of nanoparticles, including their interaction with the immune system, is a growing area of interest. This study presents a one-pot synthesis method for 15 nm L-cysteine or D-cysteine capped gold nanoparticles (L/D-Cys-GNPs) and evaluates their immunological potential as adjuvants in mice. The synthesized GNPs were comprehensively characterized using UV–visible absorption spectroscopy, FTIR, CD spectra, and TEM, revealing enhanced stability and effective internalization by human umbilical vein endothelial cells (HUVEC), with L-Cys-GNPs exhibiting a higher uptake rate. In vivo immunization studies demonstrated that L-Cys-GNPs significantly boosted the production of anti-ovalbumin(OVA) IgG antibodies compared to D-Cys-GNPs (>66 folds), underscoring the importance of chiral surface properties in modulating immune responses. However, the encapsulation of GNPs in liposomes negated the chiral effect, suggesting that delivery methods may influence the interaction of GNPs with the immune system. The findings highlight the role of chirality in vaccine development and provide insights into targeted antigen delivery systems. This work contributes to the understanding of chirality in vaccine development and paves the way for the design of more effective vaccines against challenging diseases.

Exploring conformational changes in β-lactoglobulin (β-LG) induced by silibinin: A comprehensive analysis of polyphenol-protein interaction

This study investigates the comprehensive characterization of the interaction between β-lactoglobulin (β-LG) and Silibinin using various spectroscopic techniques. Fluorescence quenching experiments at different temperatures (298, 303, 308, and 313 K) revealed substantive interactions between β-LG and Silibinin, as indicated by a reduction in fluorescence intensity and a red shift in emission maxima. Further analysis, including Stern-Volmer quenching constants (KSV), bimolecular quenching rate constants (kq), and thermodynamic parameters demonstrated static quenching mechanism and strong binding affinities (Ka range: 0.138–1.483 × 105 M−1) between BLG-Silibinin complex. Thermodynamic study suggested positive enthalpy and entropy changes (ΔHo=43.31 kcal mol−1; ΔSo=164.33 cal mol−1 K−1), suggesting a spontaneous reaction with negative ΔGo values (-5.66 to -7.30 kcal mol−1). Forster resonance energy transfer (FRET) measurements confirmed optimal distances (r and Ro) for FRET occurrence, endorsing the static quenching mechanism. Molecular docking supported these findings, showcasing a 1:1 stoichiometric binding ratio for β-LG: Silibinin. The β-LG and Silibinin complex is primarily stabilized by hydrogen bonds and hydrophobic interactions. Molecular dynamics simulations over 200 ns highlighted stability in the β-LG-Silibinin complex, indicated by RMSD convergence, consistent RMSF values, and compactness illustrated by Rg. Conformational changes in β-LG upon Silibinin binding were further confirmed through UV-Vis absorption spectroscopy, FTIR, far-UV CD, synchronous fluorescence, and 3D fluorescence analyses. Functionally, the antioxidant capacity of β-LG increased after complexation with silibinin as quantified by DPPH assay. These results collectively depict the intricate network of interactions between Silibinin and β-LG, shedding light on the molecular details of their binding and offering insights into potential functional implications in biological contexts.

Quantifying cellulose content in plastic-cellulose material mixtures

This study investigates the capabilities of various measurement techniques for quantifying the cellulose content in reject material from a carton recycling center, which consists of polyethylene, cellulose, and aluminum, along with impurities. Different measurement techniques, including Fourier Transform Infrared Spectroscopy combined with Attenuated Total Reflectance (FTIR-ATR), cellulose dissolution using cupri-ethylenediamine (CED) from plastic followed by gravimetric analysis, acid hydrolysis combined with chromatography, and Thermal Gravimetric Analysis TGA, are employed in this study. Acid hydrolysis combined with chromatography and TGA shows comparable results when compared to different techniques for analyzing pulper reject. Dissolution with CED showed also comparable results but shows higher variation than TGA or chromatography. FTIR absorbance ratio of 1025/2917 correlates with cellulose content, but it shows high variation and lacks sensitivity below 5% cellulose content in polyethylene. This limitation is attributed to factors such as the limited measurement area (1.8 mm) and the large particle size of the cellulose and LDPE mixtures, possibly caused by inadequate grinding of LDPE. In conclusion, TGA and acid hydrolysis combined with chromatography are the most reliable for quantifying cellulose content in recycling reject, providing more consistent and accurate results than FTIR-ATR or CED dissolution methods.

Aluminum phthalocyanine tetrasulfonate conjugated to surface-modified Iron oxide nanoparticles as a magnetic targeting platform for photodynamic therapy of Ehrlich tumor-bearing mice

BackgroundPhotodynamic therapy (PDT) is a targeted treatment option for cancers that are non-responding to ordinary anticancer therapies. It involves activating a photosensitizer with a light source of a specific wavelength to destroy targeted cells and their surrounding vasculature. Aluminum phthalocyanine tetra sulfonate (AlPcS4) has gained attention as a second-generation photosensitizer for its strong absorption in the red-light region. AlPcS4 can be conjugated to magnetic iron oxide nanoparticles (IONs) to provide targeted drug delivery to the tumor cells while reducing its undesired effect on healthy tissues in other body parts. MethodsMagnetic glutamine functionalized iron oxide nanocomposites loaded with AlPcS4 (IONs-NH2-AlPcS4) were synthesized via the co-precipitation method. The conjugate (IONs-NH2-AlPcS4) was characterized by TEM, Zeta potential, DLS, FTIR, and UV–VIS absorption spectroscopy. Furthermore, its photodynamic activity was investigated using albino mice with induced Ehrlich solid tumors. ResultsAlPcS4 was successfully conjugated to IONs-NH2 with a high loading efficiency of 54±2%. The synthesized conjugate exhibited a spherical shape, with 7 ± 2 nm particle size. The In vivo experiment revealed that the albino mice with induced Ehrlich solid tumor that were treated by combined PDT and magnetic targeting conjugate exhibited significant tumor regression and notably higher levels of necrotic tissue compared to the animals in other groups. ConclusionPDT mediated by magnetic targeting significantly inhibited tumor growth with minimal adverse effects, indicating its great potential as a promising strategy for solid cancer treatment.

Evaluation of the reactivity of co-combustion of wheat straw and waste rubber thermolysis char

The co-combustion of wheat straw (WS) and waste rubber thermolysis char (WRTC) was examined with the perspective of utilizing WRTC as a high-calorific value fuel addition to agricultural biomass. The study investigated the effect of different proportions of WS-WRTC blends (10/15/25/49 wt% WRTC) and a maximum of 4 wt% binders, including potato starch and calcium oxide, on the reactivity of co-combustion and the distribution of products during the process. Thermogravimetric analysis with Fourier Transform Infrared Spectroscopy (TGA-FTIR) analyses was employed at a temperature range of 25–1000 ° C with a heating rate of 10 ° C/min. The kinetics of co-combustion were analyzed using the Fraser-Suzuki (FS) deconvolution method and a model-based kinetic modeling. The results indicate that a 10% addition of WRTC char reduces the intensity and rate of combustion and prolongs the combustion time. It was observed that the optimal addition to the blend is 25% WRCT, and it resulting in a reduction in activation energy and combustion indexes. However, it remains with no significant impact on process stability and efficiency. Kinetics of the decomposition of the WRTC25 mixture modeled by the deconvolution method indicates a 5-step reaction course, which is a combination of the characteristic combustion stages of both fuels. The main denoted functional group observed in the FTIR absorption spectra were C=O, C-O, O-H, and C-H related to the release of CO2, CO, H2O, CH4, aromatic compounds, and hydrocarbons.

Colorimetric and Fluorimetric Detection of Fe(III) Using a Rhodamine-Imidazole Hydrazone Based Chemosensor: Photophysical Properties, DFT, TGA, and DSC Studies.

Rhodamine-imidazole hydrazones (RIH-1 & RIH-2) based chemosensors have been synthesized. These are characterised and evaluated by FT-IR spectroscopy, 1H-NMR, 13C-NMR, LCMS, absorption and fluorescence spectroscopy. These chemosensors exhibit enhanced sensitivity and selectivity in detecting the biologically significant Fe3+ metal ion through both colorimetric and fluorescence changes. The optical properties have been investigated using binary acetonitrile-water (7:3 v/v) semi-aqueous solution. The probe RIH-1 can be deployed as a fluorescent and colorimetric probe for the detection of Fe3+ ion. It shows an absorption band at 559nm and an intensity band at 579nm increasing up to 50-fold with the increase in the concentration of Fe3+ with the detection limit as low as 11nM. In the visible light, RIH-1 helps in the detection of Fe3+ ion through the naked eye, while the addition of Fe3+ to the probe RIH-1 results in a colour change from colourless to pink. This is primarily due to the opening of the lactone ring in RIH-1. Notably, RIH-1 probe displays a high quantum yield of 0.51, after binding with Fe3+ ions. Indeed, it has been found that sensor RIH-1 is very effective in sensing Fe3+ ions through both fluorescence based and visual detection methods. Additionally, DFT studies of these chemosensors have been evaluated, TGA and DSC analysis showed good thermal stability.

Multi-level fingerprinting and immune activity evaluation for polysaccharides from Dioscorea opposita Thunb.

To establish the quality control method of Dioscorea opposita Thunb., the multi-level fingerprinting of polysaccharides was established and the relationship between fingerprint and immune activity was analyzed. The two molecular weight segments Mw1 (1.38 × 105–1.63 × 106 Da) and Mw2 (3.27 × 103–4.37 × 103 Da), thirteen infrared absorption peaks (3399.26 cm−1, 2929.32 cm−1, 1631.78 cm−1, 1400.39 cm−1, 1351.80 cm−1, 1123.58 cm−1, 1024.76 cm−1, 931.53 cm−1, 854.76 cm−1, 760.43 cm−1, 708.14 cm−1, 616.47 cm−1, and 526.78 cm−1), and four monosaccharides (Man, Rha, GalA, and Glc) were used to evaluate the quality of Dioscorea opposita Thunb. The molecular weight fragments of Mw1, FT-IR absorption peaks of 1631.78 cm−1, and two monosaccharides (Man and Glc) would be used to identify Dioscorea opposita Thunb. polysaccharide (DOP) from different origins. The relationship of spectrum-effect showed that polysaccharides with features such as higher Mw1, a lower peak height of 1631.78 cm−1, higher content of Man, and lower content of Glc exerted stronger immune activity. In conclusion, this study established a polysaccharide-based quality evaluation method for Dioscorea opposita Thunb. and explored the relationship between polysaccharide fingerprints and in vitro immune activity, which provided a basis for further research on Dioscorea opposita Thunb.

Lignin Nanoparticles as pH-responsive Nanocarriers for Gastric-Irritant Oral Drug Aspirin.

Although lignin is one of the most naturally abundant biopolymers, the overall status of its utilization has long been subpar. The ability of Lignin to readily self-assemble into nanoparticles, along with its good biocompatibility and minimal toxicity, makes it a perfect agent for nanocarriers and drug delivery. Hence, in this study, we have attempted to examine lignin nanoparticles (LNPs) as an efficient pH-responsive nanocarrier for gastric-irritant oral NSAID, aspirin. Alkali lignin (AL) was extracted from rice straw via alkaline treatment, and the lignin nanoparticles were synthesized from lignin using the acid precipitation method. The average particle size was 201.37 ± 1.20 nm, and the synthesized LNPs exhibited a spherical shape and smooth outer surface along with high polydispersity (PDI= 0.284 ± 0.012). The LNPs showed moderate hemocompatibility during in vitro hemolysis studies. The nanoparticles presented nearly similar chemical structures to the AL from which they were developed, and the FT-IR absorption spectra confirmed the similarity of this chemical structure to the LNPs and AL. Aspirin was successfully loaded into the LNPs with a satisfactory drug loading value of 39.12 ± 1.50 and an excellent encapsulation efficiency value of 91.44 ± 0.59. Finally, the LNPs were capable of protecting the loaded drug at the acidic pH of the stomach (1.2) with just 29.20% release of the loaded aspirin after 10 h of observation in vitro. Contrarily, the LNPs were capable of rapidly releasing the aspirin at the basic pH of the intestine (7.4) with nearly 90% release of the loaded drug after 10 h observation in vitro. The basic pH of the intestine might lead to gradual dissociation of the LNPs followed by swift release of the loaded cargo. These findings substantiate that the LNPs carry the potential to be an apt and safe nanocarrier for oral drugs like aspirin as well as parenteral drugs, and LNPs can be utilized as an efficient alternative to enteric coating.

Effect of Calcination Temperature on the Surface of Prepared ZnO Nanocatalysts

ZnO nanoparticles (NPs) having nsemiconducting properties are important nanocatalysts for many surface reactions. Because of their extensive use as heterogeneous nanocatalyst for energy production and environmental cleaning, it is essential to understand their surface properties to design better chemical and photochemical nanocatalysts. Here, we used the sol-gel method to develop numerous ZnO NPs at various calcination temperatures (300 - 800 oC) and analyzed by different surface characterization techniques such as FTIR, SEM, XRD and UV-visible absorption spectroscopy. To investigate the catalytic activity a series of photooxidation studies on Remazol Red RR (RRR) were carried out at different conditions. From the surface characteristic analysis, it is found that the crystalline ZnO NPs are formed at above 400 oC temperature. The highest photocatalytic efficiency is found at 500 oC which might be related to the lowest particle size (35.4 ± 5.2 nm) and surface heterogeneity. The experimental results suggest that temperature-controlled growth rate and intra/inter-particle heterogeneity of ZnO nanoparticles have a great impact on the surface properties and photocatalytic activity. In addition to surface area, surface defects and crystal deformation may have a considerable impact on the photocatalytic activity by ZnO NPs. Finally, this study will help to understand what type of surface properties need to optimize to design industrial suit ZnO nanocatalysts. Journal of Engineering Science 15(1), 2024, 75-81

Healing Potential of the Marine Polysaccharides Carrageenan and Ulvan on Second-Degree Burns.

The treatment of second-degree burn wounds presents a significant clinical challenge, often characterized by prolonged healing times and risk of complications. In this study, the wound healing potential of bioactive marine sulfated polysaccharides ulvan and carrageenan formulated in gels at concentrations of 1.5%, 5.0%, and 10% w/w was evaluated. Hairless female SKH-hr2 mice (n = 7 per treatment) with burn-inflamed skin were treated with the polysaccharide-based gels, and the therapeutic efficacy was assessed using a comprehensive array of evaluation methods, including a histopathological analysis, clinical observation, photo-documentation, an image analysis, an evaluation of biophysical skin parameters, and FT-IR spectroscopy. Our findings indicate that the 10% w/w carrageenan gel exhibited significant enhancement in wound healing, particularly in the early stages of the healing process. This was evidenced by the restoration of the α-helix structure of collagen and the configuration of glycosaminoglycans, as demonstrated by FT-IR absorption bands of the skin both in vivo and ex vivo. Furthermore, the 5% w/w ulvan gel also demonstrated notable efficacy in promoting wound healing, particularly in the later stages of the healing process. These results suggest that carrageenan and ulvan gels hold promise for improving the efficiency of wound healing in second-degree burn wounds. Our study contributes to the understanding of the therapeutic potential of marine polysaccharides and provides insights into their mechanism of action in promoting wound healing.

Cinnamon essential oil incorporated chitosan submicron emulsion as a sustainable alternative for extension of mango shelf life

In the present study, cinnamon bark essential oil (CEO)-incorporated chitosan-based submicron emulsion coatings (CEO-CSSEs) were successfully prepared by an ionic gelation method using sodium tripolyphosphate (STPP) as a crosslinking agent and Tween 20 as a surfactant. A chitosan:CEO mass ratio ≤1:0.5 was found to have a unimodal and narrow size distribution. The FTIR absorption bands confirmed the successful encapsulation of CEO into the chitosan particles, which exhibited a spherical shape and aggregated regions with cracks. Acute oral toxicity tests revealed that the cinnamon bark essential-loaded chitosan submicron emulsion was nontoxic and could be used for coating mango fruits. Postharvest submicron emulsion coatings on mangos significantly delay physio-chemical changes linked to ripening. However, mangos coated with CEO-CSSEs at 1:0.75 and 1:1 ratios remained unripen, while those coated with CEO-CSSEs at 1:0.5 ratio ripened slowly, implying a negative impact of CEO at higher concentrations on mango quality and shelf quality. Therefore, it is concluded that CEO-CSSEs at 1:0.5 successfully slowed different physio-chemical parameters linked to the deterioration of mango quality; thus, treatments can be suggested to extend the shelf life to 18 days during ambient storage at 25 ± 2 °C and 65% RH.

Role of Nd (III) ions on B2O3–TeO2-GeO2-MgO glass composition for optical and ionizing protection application

In this investigation, we reported three glass samples of Nd (III) ions doped boro-tellurite-germanite glasses. The chemical composition of (35-x) B2O3–20TeO2-10GeO2-35MgO-xNd2O3 where x = 2.5, 5, and 7.5, all in mol%, was used to synthesize an optical glass. XRD, FTIR, and optical absorption were utilized to evaluate the structural and optical properties of Nd2.5, Nd5.0, and Nd7.5. X-ray diffraction was measured in the spectra range of 10–80°. Additionally, spectra of FT-IR in the wavenumber range of 400–4000 cm−1 were reported to investigate all structural groups. Several absorption peaks related to the transitions from ground level 4I9/2 to the other excited state were investigated. Various mechanical, optical, and physical properties were calculated theoretically and analyzed to determine the role of the rare earth ions (Nd3+). The optical electronegativity (χ) and optical basicity (Λ) results showed a reduction in the strength of the bond and formed an ionic bond in the glass structure due to adding Nd2O3. These results align with the reduction in the elastic modulus results by adding Nd2O3 instead of B2O3. Radiation shielding parameters like HVL, TVL, MFP, and Zeff were thoroughly reported for all Nd2.5, Nd5.0, and Nd7.5, which showed slight improvement when Nd2O3 was added instead of B2O3.

Highly Sensitive and Selective Recognition of Zn2⁺ and Fe2⁺ Ions Using a Novel Thiophene-Derived Hydrazone Dual Fluorometric Sensor.

The selective detection of Zn2⁺ and Fe2⁺ ions is critical in environmental and biological studies. Schiff base chemosensors hold promise, but exploration of thiophene-derived variants remains limited. This work introduces a novel thiophene-derived Schiff base sensor (TBH), synthesized through the condensation reaction of thiophene-2-carboxaldehyde with benzil-bis-hydrazone, for the selective detection of Zn2⁺ and Fe2⁺ ions. TBH exhibits remarkable selectivity, with a significant 185-fold fluorescence enhancement for Zn2⁺ and complete quenching 99% for Fe2⁺, allowing for distinct detection of both ions. Notably, TBH demonstrates high binding affinity towards Zn2⁺ and Fe2⁺, even in the presence of competing cations, forming stable 1:1 complexes. This finding is supported by absorption and emission titration studies and FT-IR analysis as well. This easily synthesized, rapid and cost-effective sensor offers a promising approach for sensitive and differentiated dual detection of Zn2⁺ and Fe2⁺ in environmental and biological systems.

Temperature Dependent near Infrared Spectroscopy of Electron Irradiated Ceria Single Crystals.

The FTIR absorption bands of virgin and electron-irradiated CeO2 single crystals were measured from 20 K to 500 K between 4000 cm-1 and 12,000 cm-1 (~830 nm to 2500 nm). Three broad bands centered at about 6100 cm-1 (~0.75 eV), 7000 cm-1 (~0.87 eV), and 10,500 cm-1 (~1.3 eV) were recorded above 100 K for the 2.5 MeV electron energy. Two smaller bands at about 4300 cm-1 (~0.53 eV) and 5500 cm-1 (~0.68 eV) were also recorded below 100 K. Similar broad bands centered at about 4100 cm-1 (~0.52 eV), 6400 cm-1 (~0.79 eV), 7600 cm-1 (~0.94 eV), and 10,500 cm-1 (~1.3 eV) are also found for the 1.4 MeV electron energy above 300 K. The evolution of these absorption bands was followed as a function of temperature. The plots of band intensity ratios show a thermally activated process corresponding to the ionization of the deep electronic levels of point defects in the band gap of ceria of ~26,000 cm-1 (~3.2 eV). These five bands are assigned to the different charge states (0, -1, -2, -3, -4) of the Ce vacancies produced by elastic collisions above 1.0 MeV.

Green synthesis of silver nanoparticles from Manilkara zapota leaf extract for the detection of aminoglycoside antibiotics and other applications.

Antibiotics of aminoglycoside (AMG) class, such as streptomycin (STR), have been widely used to treat infectious diseases caused by Gram-negative bacteria in livestock and humans. In this study, a selective and sensitive colorimetric probe for the determination of STR was proposed based on eco-friendly green synthesized AgNPs from the leaf extract of Manilkara zapota. The mechanism for the detection of STR is based on the electrostatic interaction of opposite charges between negatively charged silver nanoparticle-Manilkara zapota leaf (AgNP-MZL) and STR, causing an aggregation-induced characteristic shift of the SPR band (from 390 nm to 570 nm wavelength) of AgNP-MZL. The morphology, size distribution and optical properties of AgNP-MZL were characterized using UV/visible absorption spectroscopy, FTIR spectroscopy, XRD, DLS, zeta-potential measurements and TEM. The selective determination of STR was experimentally confirmed by performing controlled testing with other classes of antibiotics. To test the sensitivity level of this method, the ratio of these two A 390/A 570 absorbance wavelengths was selected to provide a linear concentration plot between 5 and 100 ng mL-1 STR. The LOD and LOQ were calculated to be 3.5 ng mL-1 and 26.8 ng mL-1, respectively. Good precision was evaluated with a standard deviation of 0.45 ng mL-1 and a relative standard deviation of 2.0% (intraday) and 2.42% (interday) at 10 ng mL-1 for 3 replicate measurements. Advantages of the green synthesis of AgNP-MZL include its eco-friendly nature and it is easy, efficient, cost effective and selective for the detection of the AMG class of antibiotics, i.e. STR, in agricultural and environmental samples.

Investigation on the Drug Release Efficacy of the Ibuprofen-Loaded ZIF-8/Fe3O4 NPs Nanocarrier.

In this work, a one-pot multicomponent synthesis of the ibuprofen-loaded Fe3O4 nanoparticles-supported zeolitic imidazolate framework-8 (Ibu-ZIF-8/Fe3O4 NPs) nanohybrid was carried out. The ZIF-8/Fe3O4 NPs nanohybrid was used as a drug carrier for the in vitro release of ibuprofen in a PBS solution. The structure and morphology of the synthesized materials were investigated by powder X-ray diffraction (PXRD) analysis, transmission electron microscopy (TEM) analysis, UV-visible absorption studies, FTIR spectroscopy, and thermogravimetric analysis (TGA). The ibuprofen release kinetics was studied by UV-visible spectroscopy. The mechanism of drug delivery was thoroughly investigated and the Higuchi model was found as the best-fitted model for the ibuprofen release study. The 20 wt % Fe3O4 NPs-supported ZIF-8 nanohybrid exhibited more than 95% ibuprofen release efficiency in phosphate buffer saline of pH 7.4 within 2 h. The separation ability of the nanohybrid was very good, and it was easily separated by a simple commercial magnet. In order to investigate the cell viability, the cytotoxicity of ZIF-8, Fe3O4 NPs, and ZIF-8/20 wt % Fe3O4 NPs was investigated using MTT assays against Leishmania donovani promastigotes. The ZIF-8/20 wt % Fe3O4 NPs nanohybrid carrier exhibited a cell growth inhibition effect with a high correlation coefficient and low probability (p) values. The high release of drug molecules may be due to the more open site of the ZIF-8/Fe3O4 NPs nanohybrid. The drug release profile suggests that the nanohybrid can be potentially used as a drug carrier for targeted drug delivery systems.

A new look at an explanation of band gap of PECVD grown a-Si:H thin films using absorption spectra, spectroscopic ellipsometry, Raman, and FTIR spectrosopy

Amorphous silicon is seen to be among the most promising materials for solar cell applications because of its higher temperature coefficient of resistance, adjustable forbidden-band gap, enhanced optical absorption, and capacity to reduce solar module costs. Changes in deposition rate, absorption coefficient and optical band gap of a-Si:H films with varying silane flow rate show that SiH4 molecules density influence the plasma growth process. Silane flow rate affects the percentage of silicon atoms during processing. The deposition rate of a-Si: H films increased from 14.36 nm/min to 15.97 nm/min by increasing silane flow rate from 25 sccm to 45 sccm. Broadening of optical band is observed. Films deposited at 35 sccm of silane flow rate shows the higher absorption coefficient. All films are characterized by FTIR, Raman spectroscopy, spectroscopic ellipsometry and optical absorption to understand the changes in band gap. The band gap Eg of all films is correlated with microstructure factor, Q factor, bond angle deviation Δθ and width of Si–H2 mode to analyse the effect of defects, disorders and microvoids.