Fourier Transform Infrared Spectroscopy Spectral Analysis Research Articles

Comparative analysis of biofilm structures in Salmonella Typhimurium DMC4 strain and its dam and seqA gene mutants using Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy methods.

It is well-established that the dam and seqA genes act in the biofilm production in Salmonella. However, the molecular basis underlying this activity remains unexplored. This study aims to address this gap in the literature. In this study, comparative Fourier Transform Infrared (FT-IR) Spectroscopy and Raman spectral analyses were conducted to investigate the molecular basis of decreases in swimming, swarming motility, and biofilm characteristics observed in the dam and seqA gene mutants of S. Typhimurium DMC4 wild-type strain. The comparative analysis revealed a pronounced reduction in proteins, lipids, carbohydrates, and nucleic acids within the biofilm structures of mutant strains. These findings confirm that these macromolecules are crucial for the integrity and functionality of biofilm structures. FT-IR analysis showed that while amide-I bands decreased in the biofilm structures of mutant strains, amide-II bands increased compared to the wild-type strain. Similarly, Raman analyses indicated an increase in amide-IV bonds and a decrease in amide-V bonds. The parallelism between FT-IR and Raman spectral analysis results, particularly regarding amide I, amide V, amide II, and amide IV bands, is noteworthy. Additionally, these findings may lead to the development of markers for rapidly diagnosing transitions from planktonic to biofilm form in Salmonella. The substantial decrease in β-glucans and lipids, including cellulose, within the biofilm matrix of mutant strains highlights the critical role these polymers play in swimming and swarming motility. Given the clinical and industrial importance of Salmonella biofilms, it is crucial to develop strategies to prevent biofilm formation and identify target molecules that can inhibit biofilm formation. The results of our study suggest that β-glucans and amides are essential targets in the effort to combat Salmonella biofilms.

Ginger (Zingiber officinale)-Mediated Green Synthesis of Silver-Doped Tin Oxide Nanoparticles and Evaluation of Its Antimicrobial Activity.

Green synthesis of nanoparticles using plant extract is a novel development that has gained significant attention because of its low cost, nontoxicity, and environmental friendliness. In the present study, silver-doped stannic oxide (Ag-doped SnO2) nanoparticle was synthesized by an eco-friendly green synthesis method. The synthesized samples were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and their antimicrobial activities were assessed against two bacteria Escherichia coli (E. coli) and Staphylococcus aureus (S. aurus) and two fungi Fusarium oxysporum (F. oxysporum) and Fusarium graminearum (F. graminearum) by using the disk diffusion method. Ag-doped SnO2 nanoparticles show a strong and broad absorption from UV-vis spectra when compared to pure SnO2 nanoparticles. FTIR spectral analysis revealed that the peak at 505.69 cm-1 was assigned to Sn-O and O-Sn-O stretching vibration of SnO2 nanoparticles. XRD analysis confirmed the formation of a tetragonal rutile structure with average particle size ranging from 10 to 17 nm. The antimicrobial result indicates that the Ag-doped SnO2 revealed significant antimicrobial activity against both bacterial and fungi strains with the zone of inhibition of 29 ± 0.54, 27 ± 0.05, 17 ± 0.05, and 15 ± 0.05 mm for S. aureus, E. coli, F. oxysporum , and F. graminearum, respectively. Thus, the studies suggested that Ag-doped SnO2 nanoparticles exhibit good activity against both Gram-negative and Gram-positive bacteria and fungi. This is because doping SnO2 nanoparticles with metallic elements such as Ag has been used to enhance their performance, confirming them as a good candidate for antimicrobial agents and the development of future therapeutic agents.

Comparative Analysis of Chemical, Microbiological, Sensory and Volatile Compound Profiles in Manouri PDO and Artisanal Manouri Cheeses: A Preliminary Study

Manouri, a protected designation of origin (PDO) cheese, is one of the most popular whey cheeses produced in Greece. The objective of the current study was to investigate if there are differences between artisanal and industrial Manouri cheeses regarding microbiological quality, volatile organic compounds (VOCs) profile and other quality parameters (colour, texture), sensory attributes and spectral characteristics detected by Fourier transform infrared spectroscopy (FT-IR) that may discriminate the samples. Differences were detected in the population of the dominant microbial groups, especially for lactic acid bacteria (LAB), Enterobacteriaceae and yeast counts. No discrimination was attained from the physicochemical analyses, except for the pH values. A total of 50 VOCs were identified, including ketones, lactones, free fatty acids, aldehydes, esters, alcohols and hydrocarbons. Sensory evaluation was carried out using a quantitative descriptive analysis (QDA) panel and a consumer panel. Consumers showed a preference for the artisanal Manouri, and the QDA panel revealed significant differences in 11 out of the 17 sensory attributes. Colour and texture analyses were also performed and showed specific differences in yellowness, as well as in fracturability and hardness. FT-IR spectral analysis demonstrated potential discrimination related to the phospholipid content and profile of artisanal and industrial Manouri.

An FTIR-based model for the diagenetic alteration of archaeological bones

Bones and teeth from archaeological records are direct evidence of past individuals and they represent valuable archives for palaeo-anthropological and palaeoenvironmental studies. However, pristine information may be obliterated by the diagenetic alteration of bone specimens. Thus, defining in detail their preservation state is fundamental to assess the potential of extracting information about the past life of the individual, as well as to investigate the palaeo-environment at the burial site. For this reason, we have selected a set of archaeological samples (petrous bones and tooth roots) of different origin and chronology that have experienced diverse environmental and burial conditions, from arid and semi-arid to temperate regions in a time span from prehistoric to fresh bones. Thus, the selected samples underwent a variety of diagenetic processes, resulting in different types and extent of alteration patterns. Here we have applied a minimally-invasive sampling strategy and an analytical protocol based on Fourier transform infrared spectroscopy (FTIR) in order to ensure the investigation of a statistically significant set of samples. We provide a method to describe and quantify the changes in the physico-chemical properties of both the organic and inorganic constituents of bones, by establishing a set of parameters calculated from the FTIR spectra and evaluating their sensitivity in describing the alteration types and extent in bone specimens. Through FTIR spectral analysis, we have defined the most suitable parameters to effectively describe the alteration degree of bone specimens. Notably, the results have shown that, despite the complexity of multifactorial diagenetic processes, their measurable effects on differently altered bones can be described by a common mechanism. This indicates a progressive loss of collagen which is paralleled to the recrystallization of bioapatite and the loss of structural carbonate, regardless of the origin and chronology of the specimens. Thus, here we propose an FTIR-based model for bone diagenesis of general validity, highlighting that distinct diagenetic processes affecting the archaeological bones have acted according to common alteration mechanisms.

Tunable thermal property of poly(styrene-alt-phenylmaleimide)-based alternating copolymers through mediated hydrogen bonding strength

The glass transition temperature (Tg) value of poly(styrene–alt–hydroxyphenylmaleimide) (poly(S–alt–HPMI)) is much higher than poly(styrene–co–vinyl phenol) due to the presence of the maleimide unit in poly(S–alt–HPMI) and its intramolecular screening effect result in a substantially higher Tg value. In this study, our focus was revolved about the impact of para–OH groups with different combinations and their influence on their Tg values. To achieve this, six alternating copolymers using free radical copolymerization were synthesized and performed them to comprehensive characterizations including Fourier–transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), matrix–assisted laser desorption ionization/time of flight (MALDI–TOF) mass spectrometry, and gel permeation chromatography (GPC), which were crucial in confirming the chemical structures and sequence distributions of these alternating copolymers. We employed the 2D–FTIR spectral analysis method, comparing copolymers with OH groups on the styrene unit, the phenylmaleimide unit, or both to understand the diverse effects of OH groups. Furthermore, we compared these findings with acetoxy–styrene (AS) derivative copolymers and poly(styrene–alt–phenylmaleimide) (poly(S–alt–PMI)), which lacks any hydrogen bonded donor units. As a result, this work not only contributes to a valuable understanding of the role of hydrogen bonding in polymeric materials but also provides deeper insights for designing polymers with tunable thermal properties by strategic placement of OH groups.

Assessment of historic buildings after an earthquake using various advanced techniques

Monuments are structures with historical, archaeological, and cultural qualities. They were not designed or constructed to be earthquake resistant, and so pose risks to the community and are vulnerable to collapse or irreversible damage, particularly in seismically active areas. This study conducted a condition assessment of two different historic buildings to estimate their functional life following an earthquake on Samos Island on October 30, 2020. The study combined laboratory analysis, polarized optical microscope analysis, and FTIR (Fourier Transform Infrared Spectroscopy) spectral data analysis along with advanced techniques, such as Ground Penetrating Radar (GPR), thermal imaging, and Resistivity Measurement (RM). The signal and image analyses demonstrated the successful application of an integrated approach, with implications for protecting the constructed cultural heritage for a covering both scientific maintenance and decision making.

Studying the structural properties of Mg-Zn ferrite nano partical prepared by auto combustion Sol-gel method

In the present work the Magnesium-zinc ferrite chain ( Mg1-xZnxFe2O4) with x=0-1,were synthesized using sol-gel auto combustion as a modern chemical ‎methods .Nitrates, citric acid and ammonia were used ‎in order to get ferrite nano powders at temperature 2200C , which characterized a higher dispersion ‎and homogeneity with particle size in the range of (27.47-68.9) nm. The obtained ferrite nano powder calcined at temperature 5000C for a period three hours .
 Samples examined by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). From FTIR spectral analysis the structure of the spinel ferrites shows two absorption bands, , due to vibration of octahedral and tetrahedral metal oxygen bonds. SEM results show the presence of uniformly distributed and almost spherical shaped particles

Hydrolysis, Microstructural Profiling and Utilization of Cyamopsis tetragonoloba in Yoghurt

The present study investigates the hydrolysis, microstructural profiling and utilization of guar gum (Cyamopsis tetragonoloba) as a prebiotic in a yoghurt. Guar galactomannans (GG) was purified and partially depolymerized using an acid, alkali and enzyme to improve its characteristics and increase its utilization. The prebiotic potential of hydrolyzed guar gum was determined using Basel and supplemented media. Crude guar galactomannans (CGG), purified guar galactomannans (PGG), base hydrolyzed guar galactomannans (BHGG), acid hydrolyzed guar galactomannans (AHGG) and enzymatic hydrolyzed guar galactomannans (EHGG) were analyzed using scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Yoghurt was prepared with a starter culture and incorporating guar gum, its hydrolyzed forms (0.1, 0.5 and 1%) and Bifidobacterium bifidum. The results showed that PHGG significantly improved the viability of B. bifidum. SEM revealed a significant change in the surface morphology of guar gum after acidic and enzymatic hydrolysis. Enzymatic hydrolysis developed a well-defined framework within guar gum molecules. The XRD pattern of CGG, PGG and AHGG presented an amorphous structure and showed low overall crystallinity while EHGG and BHGG resulted in slightly increased crystallinity regions. FTIR spectral analysis suggested that, after hydrolysis, there was no major transformation of functional groups. The addition of the probiotic and prebiotic significantly improved the physiochemical properties of the developed yoghurt. The firmness, cohesiveness, adhesiveness and syneresis were increased while consistency and viscosity were decreased during storage. In sum, a partial hydrolysis of guar gum could be achieved using inexpensive methods with commercial significance.

FTIR spectral correlation with alpha-glucosidase inhibitory activities of selected leafy plants extracts

Fourier transform infrared spectroscopy (FTIR) is a simple, rapid analytical technique used for the identification of organic functional groups of biomolecules. This study aimed to investigate the use of FTIR spectroscopy method for rapid detection of the α-glucosidase inhibitory activity of crude extracts of edible leafy plants, characterization of functional groups of chemical components present in crude extracts, and identification of possible biomolecules responsible for α-glucosidase inhibitory activity. Powdered leaves of five different plants, namely Le-kola pala (LE) (Premna procumbens), Kora kaha (KK) (Memecylon umbellatum), Koppa (KO) (Polyscias scutellaria), Stevia (ST) (Stevia rebaudiana), and Yaki naran (YK) (Atlantia ceylanica) were sequentially extracted with hexane, ethyl acetate (EtOAc) and methanol (MeOH). The FTIR spectra of crude plant extracts were obtained following the KBr pellet method, within the range of 4000-500 cm-1. The plant extracts were subjected to assay the α-glucosidase inhibitory activity. Further, the multivariate predictive models for α-glucosidase inhibitory activity were developed using partial least square (PLS) regression analysis. The highest Rc2 (0.96), Rcv2 (0.87), Rp2 (0.93), and the lowest RMSEC (24.10), RMSECV (41.70), and RMSEP (81.04) values were noticed for spectral region range from 1700 cm-1 to 1800 cm-1, indicating the strongest correlation to the α-glucosidase inhibitory activity, while the spectral region range from 1500 cm-1 to 1700 cm-1 was found to have the lowest Rc2 (0.71), Rcv2 (0.52), Rp2 (0.45) and the highest RMSEC (61.14) and RMSECV (80.21), indicating the lowest correlation to the α-glucosidase inhibitory activity. As the peak appearing in the range of 1700-1800 cm-1 is usually ascribed to C=O stretching vibration of ester groups, ketones, and carboxylic acids, there was a strong correlation between α-glucosidase inhibitory activity with those organic functional groups. The present study suggests that FTIR spectral analysis together with PLS regression analysis would be a convenient, rapid tool to determine α-glucosidase inhibitory activity of plant extracts.

PHYTOCHEMICAL INVESTIGATION AND EVALUATION OF ANTIOXIDANT, AND ANTI-INFLAMMATORY ACTIVITY OF AERIAL PARTS OF Lindernia antipoda

Plant species always remain a backbone for the discovery of active biomolecules required for public health. The existing scrutiny is outlined to dissect the chemical nature and explore the antioxidant and anti-inflammatory strength of methanol extract of aerial parts of Lindernia antipoda by in vitro methods. The basic phytochemical evaluation of the extract reflected the existence of essential nitrogenous and phenolic bio-compounds. UV-visible and FTIR (Fourier Transform-Infrared Spectroscopy) spectral analysis supported the chemical nature of reflected compounds. The antioxidant capability was noticed through nitric oxide scavenging assay and ABTS [2,2’-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid)] radical cation scavenging assay while anti-inflammatory competence was examined through the stabilization approach of human erythrocytes membrane against heat-induced membrane lysis. The methanol extract showed nitric oxide scavenging and ABTS radical cation scavenging by IC50 values of 398.38 μg/mL and 513.30 μg/mL respectively while anti-inflammatory activity was observed with the IC50 value of 573.01 μg/mL. The outcomes of each activity of methanol extract are presumably linked to the essential bioactive chemical substances in the extract

Structural and Optical Properties of Graphene Quantum Dots-Polyvinyl Alcohol Composite Thin Film and Its Potential in Plasmonic Sensing of Carbaryl.

In this study, graphene quantum dots (GQDs) and polyvinyl alcohol (PVA) composite was prepared and then coated on the surface of gold thin film via the spin coating technique. Subsequently, Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and ultraviolet-visible spectroscopy (UV-Vis) were adopted to understand the structure, surface morphology, and optical properties of the prepared samples. The FT-IR spectral analysis revealed important bands, such as O-H stretching, C=O stretching, C-H stretching, and O=C=O stretching vibrations. The surface roughness of the GQDs-PVA composite thin film was found to be increased after exposure to carbaryl. On the other hand, the optical absorbance of the GQDs-PVA thin film was obtained and further analysis was conducted, revealing a band gap Eg value of 4.090 eV. The sensing potential of the thin film was analyzed using surface plasmon resonance (SPR) spectroscopy. The findings demonstrated that the developed sensor's lowest detection limit for carbaryl was 0.001 ppb, which was lower than that previously reported, i.e., 0.007 ppb. Moreover, other sensing performance parameters, such as full width at half maximum, detection accuracy, and signal-to-noise ratio, were also investigated to evaluate the sensor's efficiency.

Modifier’s influence on spectral properties of dysprosium ions doped lead boro-telluro-phosphate glasses for white light applications

Trivalent dysprosium doped Lead boro-telluro-phosphate glasses were synthesized with varying modifiers such as Li+, Zn2+, Ca2+, Sr2+, and Ba2+ using traditional route of glass preparation (melt quenching). The basic network formation and spectroscopical aspects of the as piped outed glasses was analyzed using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), UV–vis-NIR, photoluminescence (PL) and emission decay measurements. The existence of elementary functional groups pertaining to the present glass network was explored through FTIR spectral analysis. Bonding parameters (δ) were found to analyze the bonding nature of the rare earth ions and the surrounding metal ligand site. The optical bandgap, band tailing parameter and Urbach energy was found using Tauc’s method in order to identify the transparent region of the prepared glass samples. Furthermore, the symmetry of ligands around the Dy3+ ions has been explored with absorption spectral data by inspecting the Judd-Ofelt (JO) parameters and oscillator strengths of the as-synthesized samples. The radiative properties for instance branching ratios (βR), stimulated emission cross-section (σP) and lifetime (τR) of the meta stable states are estimated to realize the novel applications. The CIE colour coordinates and Y/B ratio values were estimated employing the photoluminescence spectra, whereas the colour purity and it’s colour correlated temperature (CCT) were determined following the (x,y) values thus confirms the generation of neutral white light emitting ability of the prepped samples. The decay or lifetime analysis shows the well fitted non-exponential behavior of the present Dy3+ doped Lead boro-telluro-phosphate glasses.

Condition assessment of different historic bridges using Non Destructive Techniques (NDT) with FTIR analysis in Izmir after the Samos Island earthquake

The study aimed to contribute to condition assessments of historic bridges in Izmir, Turkey and the estimation of their predictable functional lifetime after the Samos earthquake. This document is a summary of the study into the reliability of Non-Destructive Techniques (NDT) for testing the state of different historic bridges impacted by the October 30, 2020 Earthquake. Besides providing data on material characteristics, NDT can help identify hidden bridge structure defects, such as cavities and moisture. This study also used FTIR (Fourier Transform Infrared Spectroscopy) spectral data analysis in conjunction with NDT as a multidisciplinary evaluation technique and demonstrates the value of this approach in the field. This study is of special relevance to bridge engineers.

The impact of rare earth Nd3+ cations on structural, spectral, magnetic and dielectric parameters of NiFe2O4 nanoparticles

The co-precipitation route was used for the preparation of Nd-substituted NiFe2O4. The proposed general formula of prepared ferrite was NdxNiFe2-xO4. Here, “x” the moles of Nd3+ were 0.0, 0.0125, 0.025 and 0.05 in various compositions. The prepared nanocrystallites were characterized using X-rays diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and impedance analyzer. XRD patterns of all prepared samples were analyzed to confirm the phase of the materials and determine the lattice constant, crystallite size and X-rays density. The lattice parameter value varied between 8.3501 and 8.3549 Å. The average crystallite size was ∼15 nm. The FTIR spectral analysis was used to investigate the M-O stretching vibrational bands. FTIR spectra showed the stretching vibrational bands of Fe-O at octahedral and tetrahedral sites. After structural and spectral investigations, the prepared nanocrystallites were subjected to room temperature magnetic measurements by vibrating sample magnetometry (VSM) technique. The magnetic parameters were investigated from the VSM data. The magnetic parameters suggested the possible utilization of these nanocrystalline ferrites for various advanced technological applications like switching devices and high-frequency devices. The dielectric parameters were also investigated using an impedance analyzer.

Magnetite nanoparticle mediated catalytic aquathermolysis of Omani heavy crude oil

The worldwide demand for energy continues to grow and the production of heavy crude is escalating due to shortage of conventional light crude. The transportation of heavy crude oil from the head-well to the refinery is a challenging task due to its high viscosity and low API gravity. Catalytic aquathermolysis is one of the most significant and cost-effective viscosity reduction techniques employed in the up gradation of the crude oil at elevated temperatures and hence to enhance oil extraction process. In this study, catalytic aquathermolysis of Omani heavy crude oil was performed using magnetite nanoparticles (NPs). The NPs were synthesised by reverse co-precipitation method using iron salts in alkaline medium. The synthesised NPs were characterized using Scanning Electron Microscopy (SEM), X-Ray Powder Diffraction (XRD), Energy Dispersive X- Ray analysis (EDX) and Fourier Transform Infrared Spectroscopy (FTIR). The XRD results exhibited a characteristic peak confirming the high purity of iron oxide nanoparticles. The FTIR spectral analysis designated two well-defined peaks corresponding to wave numbers of 500 ​cm−1 and 630 ​cm−1, endorses the presence of Fe–O. The catalytic aquathermolysis experiments were carried out in a Parr high temperature-high pressure batch reactor at different experimental conditions. The processing parameters in temperature range of 250 ​°C - 300 ​°C, 0.1% to 0.3% catalyst loading, water to oil ratio of 1:7 to 3:7 with 24–72 ​h of reaction time. The initial pressure in the reactor was maintained at 32 ​bars and the optimization was performed using the Taguchi method to maximize the level of heavy oil. An orthogonal array was employed to analyse the effects of mean response and mean signal-to-noise ratio (S/N) to upgrade the heavy oil. The regression analysis was used to establish a relationship between the viscosity and experimental parameters. The experimental outcomes indicates that the maximum reduction in viscosity occurred at a processing temperature of 300 ​°C, 1:7 ​W/O ratio, 0.1 ​wt% of catalyst concentration and 48 ​h of reaction time. Similarly, the optimum conditions for the reduction in API gravity were obtained at 280 ​°C temperature, 3:7 ​W/O ratio, 0.2 ​wt% of catalyst concentration and a reaction time of 24 ​h.

Removal of Organic Pollutants from Textile Mill Effluent using Azadirachta Indica Powder

Due to stringent environmental regulations and increased awareness about the environment, effluent treatment has always been a key aspect of research. Textile industry is one of the oldest and technologically advanced complex industrial sectors employing variety of chemicals and large amount of fresh water consumption. These effluents contain substantial amount of organic pollutants and suspended impurities in varying compositions and hence cannot be discharged directly into the environment. The current research work focused on the utilization of Azadirachta Indica powder as a natural adsorbent for the effective removal of organic and suspended pollutants from textile mill effluent. A series of batch experimental studies were performed by varying the pH of textile mill effluent, stirring time, stirring speed and dosage of Azadirachta Indica powder. Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Dissolved Oxygen (DO), conductivity, and turbidity were estimated to study the performance of Azadirachta Indica powder in the removal of pollutants. The characterizations of Azadirachta Indica powder before and after treatment are performed using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The best processing conditions for the effective removal of pollutants from textile mill effluent was obtained at an effluent solution pH 4.0, stirring time 90 min, stirring speed 150 rpm with 1.0 g of Azadirachta Indica powder. The surface morphological structure of Azadirachta Indica powder after batch treatment using scanning electron microscopy indicated that the pollutants are accumulated in the form of clusters on the adsorbent surface. The FTIR spectral analysis indicates the chemical interaction between adsorbent powder and organic pollutants illustrate the characteristic peaks. The study demonstrates that the Azadirachta indica is a promising type of biomass for the effective removal of pollutants from textile mill effluent.
 HIGHLIGHTS
 
 In this research, Azadirachta Indica powder was employed as a natural adsorbent for the effective removal of pollutants from textile mill effluent
 Batch experimental studies were performed by varying the pH of textile mill effluent, stirring time, stirring speed and dosage of Azadirachta Indica powder and the optimum processing conditions were established
 The study demonstrates that the Azadirachta indica is a promising type of biomass for the effective removal of pollutants from textile mill effluent
 
 GRAPHICAL ABSTRACT

Impact of iron doping on structural and optical properties of nickel sulphide nanoparticles

Transition metal sulphides exhibit excellent optical, photo electrical and thermoelectric properties. These materials have attracted much attention because of its applications in the field of electroluminescence devices, light emitting displays, cathode material for rechargeable lithium battery, magnetic devices, dye degradation and optical sensors. In the present work, iron doped Nickel sulphide nanoparticles are synthesized using chemical precipitation method. Nickel chloride and Ferric chloride are used as precursors and sodium sulphide as a stabilizing agent. The performance of the synthesized nanoparticles are analysed by varying the molarity of the iron chloride from 0.01 M to 0.05 M. The synthesized nanoparticles are characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Ultraviolet Visible spectroscopy (UV–Vis) and Photoluminescence (PL) studies. FT-IR spectral analysis shows the band at 630 cm−1 corresponds to the bending vibration of metal sulphur bond (Ni-S) and the bands observed around 585 cm−1 and 456 cm−1 are ascribed to Fe–O stretching vibrations of tetrahedral and octahedral lattice sites respectively. The XRD analysis shows the crystalline nature of nanoparticles and the average nano-crystallite size is found to be 18 nm − 26 nm. The crystallite size increases with increase in the concentration of iron. The morphology of the samples is analyzed using scanning electron microscope and is found to be spherical in shape. The optical properties are characterized using UV–Vis spectral analysis and PL study. UV–Visible absorption spectra show absorption peaks of iron doped nickel sulphide nanoparticles and the band exhibits a blue shift, indicates quantum size effect. Electrochemical studies revealed two oxidation peaks at a potential about −0.3 V and 0.7 V for pure nickel sulphide nanoparticles and in addition to it, a redox peak is observed at a potential about −0.5 V due to the doping of iron into the nickel sulphide nanoparticles. The synthesized nanoparticles may be used as high-performance electrode materials for supercapacitor applications.

Preparation and application of highly efficient and reusable TBAPIL@Si(CH2)3@nano-silica-based nano-catalyst for preparation of benzoxanthene derivatives

Tetrabutylammonium prolinate ionic liquid (TBAPIL) was prepared, and mesoporous silica nanoparticles (NPs) were synthesized. Both of these were linked through propyltriethoxysilane to prepare a reusable catalyst TBAPIL@Si(CH2)3@silica NPs (TBAPILS). The formation of TBAPIL was checked through Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) analysis. X-ray diffraction analysis confirmed the structure of silica NPs and linking of TBPAIL on it. Transmission electron microscopy proved the flourishing development of silica NPs. Scanning electron microscopy graphs exposed the altering in morphology of silica NPs and TBAPILS. FT-IR analysis also confirmed the formation of TBAPILS catalyst. Moreover, the effectiveness of the TBAPILS was also checked for the synthesis of various derivatives of tetrahydrobenzoxanthenes-11-ones. The formation and structure of obtained compounds were confirmed by FT-IR, elemental analysis, 1HNMR and 13C NMR spectral analysis. The catalyst TBAPILS was found to be used successfully up to five cycles without significant loss of activity.

Rapid Microbial Quality Assessment of Chicken Liver Inoculated or Not With Salmonella Using FTIR Spectroscopy and Machine Learning.

Chicken liver is a highly perishable meat product with a relatively short shelf-life and that can get easily contaminated with pathogenic microorganisms. This study was conducted to evaluate the behavior of spoilage microbiota and of inoculated Salmonella enterica on chicken liver. The feasibility of Fourier-transform infrared spectroscopy (FTIR) to assess chicken liver microbiological quality through the development of a machine learning workflow was also explored. Chicken liver samples [non-inoculated and inoculated with a four-strain cocktail of ca. 103 colony-forming units (CFU)/g Salmonella] were stored aerobically under isothermal (0, 4, and 8°C) and dynamic temperature conditions. The samples were subjected to microbiological analysis with concomitant FTIR measurements. The developed FTIR spectral analysis workflow for the quantitative estimation of the different spoilage microbial groups consisted of robust data normalization, feature selection based on extra-trees algorithm and support vector machine (SVM) regression analysis. The performance of the developed models was evaluated in terms of the root mean square error (RMSE), the square of the correlation coefficient (R2), and the bias (Bf) and accuracy (Af) factors. Spoilage was mainly driven by Pseudomonas spp., followed closely by Brochothrix thermosphacta, while lactic acid bacteria (LAB), Enterobacteriaceae, and yeast/molds remained at lower levels. Salmonella managed to survive at 0°C and dynamic conditions and increased by ca. 1.4 and 1.9 log CFU/g at 4 and 8°C, respectively, at the end of storage. The proposed models exhibited Af and Bf between observed and predicted counts within the range of 1.071 to 1.145 and 0.995 to 1.029, respectively, while the R2 and RMSE values ranged from 0.708 to 0.828 and 0.664 to 0.949 log CFU/g, respectively, depending on the microorganism and chicken liver samples. Overall, the results highlighted the ability of Salmonella not only to survive but also to grow at refrigeration temperatures and demonstrated the significant potential of FTIR technology in tandem with the proposed spectral analysis workflow for the estimation of total viable count, Pseudomonas spp., B. thermosphacta, LAB, Enterobacteriaceae, and Salmonella on chicken liver.

Immobilization of Atrazine Using Oxidized Lignite Amendments in Agricultural Soils

Leonardite (LND), a low-grade coal, is an inexpensive material used to improve soil fertility in humic-deficient soils. Our objective was to quantify the ability of LND to immobilize atrazine (ATZ). To accomplish this, LND morphological properties, elemental composition, and spectroscopic properties were determined. We found that LND had a high organic matter content (40.53%, w/w) with a mesopore particle structure. Fourier-transform infrared spectroscopy spectral analysis confirmed the presence of aromatic molecules, all of which contributed to ATZ adsorption. The ATZ adsorption characteristics were quantified using batch adsorption kinetic and isotherm experiments. The ATZ adsorption kinetics were best described by a pseudo-second-order kinetic model while the concentrations of ATZ adsorbed (Cads) versus equilibrium concentrations (Ceq) had the best fit with the Freundlich equation compared with five other isotherms tested. The ability of LND to minimize ATZ leaching was tested using one-dimensional transport experiments with packing configurations and materials. The results revealed that up to 95% of ATZ was immobilized in the LND-amended soil. The extractable ATZ residues from both soil and LND corroborated the reduction in ATZ leaching. Overall, the adsorption results indicated that LND had a high affinity for ATZ adsorption and could reduce ATZ transport to the groundwater.