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Abstract This study investigates the efficacy of newly synthesized inhibitor with a dual function of corrosion inhibition and biocide for control of microbial influenced corrosion (MIC) in carbon steel API 5LX in the cooling tower water (CTW) environment. Four types of N-substituted tetrabromophthalic inhibitor (N-TBI) were synthesized, and the structural characterization was performed via proton nuclear magnetic resonance spectroscopy, thermogravimetric analysis and high-resolution mass spectrometry. These studies revealed the distinctive optical, thermal, and dielectric properties of the synthesized inhibitors. The corrosion inhibition efficiency has been evaluated by the weight loss (WL) analysis and electrochemical measurements (ECM) and biofilm assay. Biofilm assays and WL showed that inhibitor II exhibited the highest inhibition efficiency 74% and 79% respectively than others. Further ECM showed that the higher charge transfer resistance and the lower corrosion current, suggesting a protective film formed on the metal surface which was due to the adsorption of the N-TBI. Fourier transform infrared spectroscopy confirmed the adsorption of the N-TBI as C–O stretching and C–H bending with the Fe complex. X-ray diffractometer revealed that the presence of inhibitors in the corrosion product (Fe3O4, Fe2O3, FeH2O2, FeS) were highly reduced than the control system. Overall, this study highlighted the potential application of N-TBI with dual function of corrosion inhibition and biocide to control the MIC for carbon steel API 5LX used in the CTW environment.

Human serum albumin (HSA) is synthesized by the liver, accounting for 60 % of total plasma protein in vertebrates' blood. It is the most predominant extracellular plasma protein that acts as a repository and transporter of exogenous and endogenous substances in the blood of healthy humans. Decreased albumin concentration in the human body or its abnormal levels indicate the occurrence of hepatic, renal, and digestive-related diseases. Therefore, accurate quantification of HSA is of great significance in diagnostic testing and routine clinical analysis of albumin-linked diseases. Herein, a class of triphenylamine rhodanine-3-acetic acid (mRA)-a bifunctional fluorescent molecule with twisted intramolecular charge transfer (TICT)-induced emission characteristics is synthesized and employed as a novel sensing probe for the fluorescent detection of human albumin. mRA can be selectively lighted up through site-specific interactions with serum albumin-binding moieties and show enhanced photophysical or biological response efficacy. Understanding the interaction of mRA with HSA at the molecular level was carried out using docking methodology to explore the site-specific interaction phenomenon. The resulting fluorescence strategy produced a dose-dependent signal response enhancement upon interaction with HSA in the concentration range of 0.01–400 μg/ml. The sensor probe exhibits a low detection limit of 10 ng/mL and is found to be a feasible, low-cost, and effective approach for HSA analysis in complex biological fluids for early detection and diagnosis of albumin-related diseases.

The global food system is plagued by legitimacy and stability issues due to climate and ecosystem disruptions, contributing to widespread malnutrition. A significant portion of the global population experiences undernourishment, overweight, and micronutrient deficiencies from unhealthy diets. Addressing these challenges necessitates regular consumption of essential nutrients from plant sources. Among various crops, Moringa oleifera leaves are highly nutritious, offering essential vitamins, minerals, and medicinal properties. Whence research was conducted to inquire the proximate phytochemical composition and extraction efficiency of moringa leaf extracts across four extraction methods: maceration (E1), Soxhlet (E2), ultrasound-assisted extraction (UAE) (E3), and microwave-assisted extraction (MAE) (E4) using 70 % hydro-ethanolic solvent. The study detected the presence of phytocompounds and phytonutrients at higher levels in UAE and MAE extracts. Recovery yield was highest for UAE (21.81 ± 0.32 %) than conventional extraction methods (6.24 ± 0.08 %). Both advanced extraction methods resulted in higher TPC (148.86 ± 1.92 mg GAE/g and 137.65 ± 4.49 mg GAE/g, respectively) and TFC (23.18 ± 0.44 mgQE/g and 22.12 ± 0.61 mg QE/g, respectively). Protein and ascorbic acid contents followed a similar trend, with UAE achieving 148.66 ± 3.74 mg/ml and 620.25 ± 1.42 mg/100g, respectively. Antioxidant activity measured by DPPH assay was highest in UAE (86.25 ± 1.58 %) along with the lowest IC50 values (11.62 ± 1.58 μg/ml) in UAE. Furthermore, ICP-OES analysis revealed higher concentrations of essential phyto-minerals in moringa leaf extracts. Moreover, SEM analysis revealed significant morphological disruptions in the leaf samples, correlating with higher phytomolecules recovery. The outcome of the research is that novel extraction methods significantly enhanced the extraction efficiency and quality of bioactive compounds from moringa leaves, suggesting their potential in the development of nutraceutical and biofortified food products to expunge malnutrition.

The rationale of this research was to explore the genetic divergence of 54 kantakari accessions (Solanum virginianum L. syn. S. surattense Burm. f.), to identify their significant traits, and unravel their genetic variations. Kantakari is a widely used medicinal plant in traditional medicine worldwide and is also known for its allopathic properties. The morphological descriptors and molecular markers (Random Amplified Polymorphic DNA) used to characterize these samples revealed significant within-accession heterogeneity, indicating the possibility of future selection. Twenty-three morphological and biochemical features were examined to assess taxonomic traits. Accessions were classified into six clusters based on Mahalanobis D2 statistics of 23 quantitative traits. Clusters V and VI had the largest intercluster distance (1183.81), whereas Cluster IV had the largest intracluster distance (D2 = 275.67) (Cluster V and VI). Random Amplified Polymorphic DNA marker amplification using 10 polymorphic primers revealed 79 alleles with an overall mean of 7.90 alleles per marker, with Polymorphism Information Content values varying from 0.11 to 0.37 (Mean = 0.30). Cluster assessment produced three distinct groups. In conclusion, the investigation underscores that substantial diversity was observed among the surveyed kantakari accessions. Using molecular markers in tandem with morphological characterization, presents a robust approach for elucidating the intricacies of species-specific genetic variation with greater accuracy and depth.

BackgroundEnvironmental soil contamination is a serious problem for humans worldwide, as it causes many diseases.MethodsThe present study focuses on utilizing biosurfactants produced by Pseudomonas stutzeri (P. stutzeri) NA3 and Bacillus cereus (B. cereus) EN6, as an electrolyte for removing chromium (Cr) from contaminated soil using the electrokinetic (EK) process.ResultsAs a result, biosurfactants produced by P. stutzeri NA3 and B. cereus EN6, being lipopeptides, increase heavy metal mobility in the EK process. The Cr removal efficiency of a novel electrolyte (biosurfactants) in the EK process was compared with that of NA3 and EN6 biosurfactants. The EK results revealed a maximum Cr removal of 75 and 70% by NA3 and EN6, respectively, at the end of 7 days.DiscussionThe biosurfactant aids in the breaking down of the heavy metals that are present deeper into the soil matrix. From the metagenomics analysis, it was identified that biosurfactant changes the microbial community with an enhanced ability to remove heavy metals. The phytotoxicity assay confirms that NA3 biosurfactant solution showed 95% seed germination and can lower hazardous pollutants in the soil.ConclusionThe application of biosurfactants as a potent electrolyte for the remediation of hazardous pollutants is an integrated process. Overall, the results of this study suggest that biosurfactants can serve as an economic and efficient electrolyte in the EK process to remove Cr from polluted soil.

In this study, the shielding properties of novel polymer composites, developed by integrating glycidyl methacrylate with nanoparticles of bismuth oxide (Bi2O3) and tungsten oxide (WO3), were explored. The ability of the composites to attenuate gamma radiation was evaluated by measuring the emissions from Ba-133, Co-60, Cs-137, and Na-22. X-ray diffraction (XRD) spectra were obtained for both the pure polymer glycidyl methacrylate and the samples containing nanostructures of Bi2O3, Bi2O3/WO3, and WO3, and scanning electron microscopy (SEM) was used to analyze the samples. The incorporation of Bi2O3 and WO3 nanoparticles into the polymer glycidyl methacrylate matrix significantly enhanced the composites' ability to attenuate gamma radiation, as demonstrated by the increased linear and mass attenuation coefficients. The results showed good agreement between the experiment and the XCOM database. The composites exhibited significant efficiency in attenuating lower-energy gamma rays, which is particularly advantageous in the medical and nuclear industries.

In this work, we developed a highly sensitive liquid scintillator (LS) using Coumarin 450 (C450) dye to detect gamma ray and localize Compton edges (CEs). C450 exhibited absorption and fluorescence peaks at 350 nm and 407 nm, respectively, in toluene, at an optimized concentration (3 mM). The LS, contained in a standard glass container (1.8 cm diameter, 3.6 cm height), showed an emission peak in the blue region, matching the high quantum yield of typical PMT photocathodes. We exposed the LS to various gamma radiation sources (137Cs, 60Co, and 22Na), recording responses for different PMT voltages. Gaussian fitting of pulse height distribution spectrum allowed CE identification at the half-height for all PMT voltages. We compared theoretical and experimental results to a GEANT4-simulated detector, obtaining CE positions for radiation interactions and scintillation photon transport. The calibrated GEANT4 simulation was compared to experimental spectra to locate the Compton edges.

BackgroundCooling towers are specialized heat exchanger devices in which air and water interact closely to cool the water's temperature. However, the cooling water contains organic nutrients that can cause microbial corrosion (MC) on the metal surfaces of the tower. This research explores the combined wastewater treatment approach using electrochemical-oxidation (EO), photo-oxidation (PO), and photoelectrochemical oxidation (PEO) to contain pollutants and prevent MC.MethodsThe study employed electro-oxidation, a process involving direct current (DC) power supply, to degrade wastewater. MC studies were conducted using weight loss assessments, scanning electron microscopy (SEM), and x-ray diffraction (XRD).ResultsAfter wastewater is subjected to electro-oxidation for 4 h, a notable decrease in pollutants was observed, with degradation efficiencies of 71, 75, and 96%, respectively. In the wastewater treated by PEO, microbial growth is restricted as the chemical oxygen demand decreases.DiscussionA metagenomics study revealed that bacteria present in the cooling tower water consists of 12% of Nitrospira genus and 22% of Fusobacterium genus. Conclusively, PEO serves as an effective method for treating wastewater, inhibiting microbial growth, degrading pollutants, and protecting metal from biocorrosion.

Background: In the intensified search to derive biologically active compounds from natural products for various health care issues, attention is focused on non-edible plant sources. Among the wild plants, Calotropis [milk weeds] of the family Apocynaceae, are the repository of pharmaceutically active phytoconstituents. The flowers of C. gigantea are expected to be rich in bioactive compounds. Methods: The bioactive compounds and in vitro anticancer activity of C. gigantea flower extract were investigated. The compounds in the extract were separated using GC–MS and confirmed their structures with NIST (National Institute of Standard and Technology) database. The cytotoxicity of flower extracts against A-549 lung cancer cell lines was evaluated by MTT assay. Among the six identified compounds, three biologically active compounds with short retention time and abundance were chosen for molecular docking for anticancer activities. Molecular docking using the software GLIDE version 6.5 was used to trace their interactions with the anti-lung cancer protein, IT69. Results: The phytochemical screening indicated the rich presence of anticancer flavonoid and phenolic compounds in the flower extract. Inhibition of cell viability and growth and morphological alterations in cells were observed when A-549 cells were exposed to different concentrations of flower extract. The highest percentage of cell death (70 %) was observed in cells exposed to 100 µg/ml concentration. Molecular docking of three identified compounds with lung anticancer protein complex, IT69 proved that Butanoic acid, 3-[(phenyl methoxy) imino] trimethylsilyl ester is a good anti-lung cancer agent. Hence for pulmonary cancer, the identified compound can intensively be tested further.

In this work, we designed a rod shape solid-state laser gain media (GM) that can produce amplified spontaneous emission (ASE) in the 630–670 nm region. The GM is made with Rhodamine B (RhB) dissolved in acetone mixed with commercially available rapid photopolymer (PP) resin that predominately (80 %) contains 3-nitro-9-octyl-9H-carbazole (NOCB) and solidified with mercury or halogen lamp. We used a solid-state matrix laser (SSL) rod of RhB embedded NOCB. The results showed that the photoluminescence (PL) of SSL was at approximately 630 m, and the absorption peak was at 575 nm. The concentration of the RhB in acetone was varied from 25 mg/ml to 100 mg/ml and mixed in a 1:10 ratio volume/weight (v/w). GM could be pumped transversely using 355 nm (3rd Harmonic of Nd: YAG) or 405 nm diode laser or a UV lamp. The GM was initially designed with the aim to be pumped using 532 nm since the resin solidified using UV and blue light irradiation. Supersizing, we found that after complete polymerization, optical pumping using 355 nm can be employed to produce ASE. The main advantage of using these SSL are (i) ease of manufacturing, (ii) simplicity to scale up, (iii) low cost, and (iv) 3D printer compatibility. It also has potential applications in the military, science, and medicine, especially facial rejuvenation.

IntroductionOintments are generally used as a therapeutic agent for topical medication or transdermal drug delivery, such as wound healing and skin lesions.MethodsIn this study, Tridax procumbens plant extract (0.7 g/mL) was used to prepare herbal-infused oil as the oil phase and gelatin-stabilized silver nanoparticle (G-AgNPs) (0.3 g/mL) as the aqueous phase. To blend the oil and aqueous phases, rhamnolipid biosurfactant with a critical micelle concentration of 55 mg/L from strain Pseudomonas aeruginosa PP4 has been used for herb ointment preparation. The average size of the synthesized G-AgNPs was observed between 10–30 nm and confirmed as spherical-shaped particles by TEM analysis. Subsequently, GC–MS and FTIR characterization are used to confirm herb ointment’s chemical and functional characteristics.ResultsBased on the antibacterial studies, the highest microbial growth inhibition was observed for herb ointment, about 19.5 mm for the pathogen Staphylococcus aureus at the concentration of 100 μg/mL, whereas 15.5 mm was obtained for Escherichia coli, respectively. In addition, the minimum inhibitory concentration (MIC) assay showed negligible bacterial growth at 100 μg/mL for S. aureus and E. coli, respectively. Moreover, the cell viability assay for herb ointment exhibited low cytotoxic activity at higher concentrations (100 μg/mL) in Vero cell lines. In this study, wound scratch assay showed a significant cell migration rate (90 ± 2%) in 3 days of incubation than the control (62 ± 2%).DiscussionAs a result, the biosurfactant-based nano-topical herb ointment revealed a low cytotoxic and higher cell migration capacity. Altogether, these findings highlighted the utility of this herb ointment in therapeutic applications such as wound healing.

Background: Marine organisms are the potential contributors of novel bioactive molecules. Nevertheless, their biodiversity and the versatility of bioactive metabolites have not been fully explored. Hence, the aim of the present study was to investigate the potentials of gut associated bacteria from a marine crab for the production of novel antibacterial compound. Methods: Aerobic gut autochthonous bacteria isolated from marine crab (Lissocarinus orbicularis) collected from Pazhayar coastal area in Nagapattinam district of Tamil Nadu, India were screened for antibacterial activity. Optimization for bacterial growth and antimicrobial compound production, extraction, purification and characterization were studied. Results: In the present study, eight morphologically distinct colonies of L. orbicularis gut associated aerobic bacterial isolates (Iso1-Iso8) on Zobell marine agar plate were selected. Isolates were screened for antimicrobial activity against human bacterial pathogens such as Salmonella paratyphi, Vibrio cholera, Vibrio parahaemolyticus, Aeromonas hydrophila and Listeria monocytogenes. On the basis of screening results, isolate 5 (Iso5) was selected as the most potential strain and identified as Paenibacillus polymyxa using biochemical and 16S rRNA sequencing methods. The sequence data was submitted to NCBI (Gene bank Accession No: MK583465). Optimization of P. polymyxa for growth and antimicrobial compound production revealed incubation period (36 h), agitation (150 rpm), pH 8.0, 35 °C, 2.5% salinity, 2% glucose and 1% yeast extract as carbon and nitrogen sources respectively were the ideal conditions and mass culture was done with these parameters. Antimicrobial compound from the cell free supernatant of mass culture medium was extracted using ethanol. The lowest minimum inhibitory concentration (MIC) of 16 μg/ml was observed against of both V. parahaemolyticus and V. cholerae. GC–MS analysis of the active ethanol fraction showed the presence of different components such as dodecane (96.72%), Tridecane (1.69%), Undecane, 2,6-dimethyl- (1.69%), Tetradecane (1.12%) and Dodecane, 2,6,11-trimethyl- (1.12%). Conclusion: The present study showed that the gut associated autochthonous bacteria of marine crabs are one of the potential sources of antibacterial compound. However, further studies are needed for the identification of the antimicrobial compound.

Background: The increasing azole drug resistance in fungal pathogens poses a pressing threat to global health care. The coexistence of drug-resistant Candida albicans with tuberculosis patients and the failure of several drugs to treat C. albicans infection extend hospital stay, economic burden, and death. The misuse or abuse of azole-derived antifungals, chronic use of TB drugs, different immune-suppressive drugs, and diseases like HIV, COVID-19, etc., have aggravated the situation. So it is vital to understand the molecular changes in drug-resistant genes to modify the treatment to design an alternative mechanism. Method: C. albicans isolated from chronic tuberculosis patients were screened for antifungal sensitivity studies using disk diffusion assay. The multidrug-resistant C. albicans were further screened for molecular-level changes in drug resistance using MDR1 gene sequencing and compared with Gen bank data of similar species using the BLAST tool. Results: The investigation proved that the isolated C. albicans from TB patients are significantly resistant to the action of six drugs. The molecular changes in MDR1 genes showed differences in seven nucleotide base pairs that interfered with the efflux pump.

Structurally interesting chromeno-quinolines were constructed via the cyclization reaction of O-propargylated naphthaldehyde and substituted anilines in good yields. We explored compound methyl-chromenoquinoline (MCQ) in detail for its optical properties using Time-dependent density-functional theory (TD-DFT) and experimental studies. The conjugated-polymer (CP) Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(2,5-p-xylene)] or [(ADS145UV or PFOPX)] was studied as donor. The TD-DFT implied that MCQ is a fluorescent compound with well-defined highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) structure at −5.327 eV and −1.836 eV, respectively, with an energy gap of 3.49 eV in toluene captivity. The TD-DFT-based model and experimental study showed an energy gap of 3.326 eV and 3.351 eV, respectively, and the deviation was 0.025 eV. The experimental studies of MCQ showed solvent-dependent fluorescence peak shifted from 445 ± 2 nm to 538 ± 2 nm for dielectric constant ranging from 0.01 (hexane) to 10.2 (water). Despite the good optical properties, MCQ produced a weak laser-induced fluorescence (LIF) and not produce amplified spontaneous emission (ASE) to any pump energy of 3rd harmonic from Nd:YAG laser (5 ns, 355 nm). When PFOPX of concentration 500 nM (500 μL) was added to MCQ of 506 mM (3.5 mL) concentration, the LIF suddenly improved tenfold due to efficient Fluorescence resonance energy transfer (FRET) process. At the optimal concentration of PFOPX (670 nM) in MCQ solution, the spectrum changed dramatically. The spectrum has five peaks with a LIF in the background, where peaks around 393.5 nm and 417.3 nm attribute to the oligomer; 438.7 nm attributed to a combined fluorescence of PFOPX and MCQ; 466.4 nm, and 493.1 nm corresponding to MCQ. Analysis shows that the peaks at 440 nm (partly) and 493 nm were ASE from MCQ.

A series of solar cells (SCs) with methylammonium mixed halide perovskite active layers with a conjugated polymer (CP) poly[2-methoxy-5-(3,7-dimethyl-octyloxy)-1,4-phenylenevinylene] and end-capped with dimethylphenyl (MDMO-PPV) as a hole transport material (HTM) was fabricated under the same experimental settings, and the performance characteristics of the individual cells were compared. For comparison purposes, we fabricated a perovskite solar cell (PSC) with a lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI)-doped sprio-OMeTAD layer (LiTSO), which showed a power conversion efficiency (PCE) of 7.68 %. The layered solar cell with a structure of TiO2, perovskite and MDMO-PPV layers showed a PCE of 5.32 % and a fill factor of 0.478. The heterojunction solar cell (HJSC) made with a perovskite and MDMO-PPV mix showed a PCE of 5.68 %. The Field emission scanning electron microscope (FESEM) showed that in HJSC, the perovskite and CP were mixed well. However, they did not penetrate deeply into the TiO2 mesoporous layer, which would hinder electron transportation and thus cause efficiency loss. The HJSC structure was tested using different thicknesses of mesoporous TiO2 (m-TiO2). At an optimal m-TiO2 thickness, the blend of perovskite and MDMO-PPV infused up to 350 nm, thus improving the PCE to 7.438 % and retaining 91 % performance even after 4 weeks of continuous operation. The perovskite/conjugated polymer blend also formed a small SC above the m-TiO2 layer, showing complete penetration of the perovskite into the m-TiO2 layer. Additionally, the formation of a pure perovskite layer on top of the TiO2/perovskite and MDMO-PPV covers neatly on top of the perovskite layer and serves as a protective layer as well as a hole transport layer. An additional layer of LiTSO on top of the HJSC further improved the PCE to 7.76 %. The use of a CP as the hole transport layer reduces the dependency on separate materials and improves the device’s stability. It could also pave the way for an easy minimalistic method for integrated, flexible power electronics that contain solar cells (perovskite/conjugated polymer), organic light-emitting diodes, and supercapacitors made of graphene.

Background: In this study, a biologically active molecule, di-methyl flubendazole isolated from the extract of Carica papaya leaves confirmed by using GC–MS, 1H NMR, and 13C NMR analysis was applied to synthesize silver nanoparticles (AgNPs). The AgNPs with plant sources an alternative therapeutic agent for synthetic compound used in cancer chemotherapy. Methods: The AgNPs were characterized using UV, FT-IR, XRD, FESEM with EDX and TEM. The antibacterial effects of AgNPs were determined with agar well diffusion method. The MTT assay used to evaluate the inhibitory effect cell lines. The acridine orange and ethidium bromide and DAPI have used cell morphological effects. Results: The AgNPs were mono-crystalline and their size ranged from 7 to 22 nm. AgNPs showed good antibacterial activity against both Gram-positive and Gram-negative bacteria. Studies on the antiproliferative potential of bioinspired AgNPs in cancer cell lines revealed that the antiproliferative effect was much stronger in HepG2 than in MCF-7 and A549 cell lines. Similarly, AgNPs exerted less cytotoxic activity in Vero cells (normal cells). AgNPs-treated cells showed necrosis, apoptotic morphology evidenced by cell shrinkage, membrane blebbing, cell decay, and necrosis. HepG2 cells treated with biosynthesized AgNPs exhibited a G0/G1 phase (52–53.37%) blockage. Compared to the control, AgNP-treated HepG2 cells showed elevated ®-actin levels; however, Bcl-2 was significantly down regulated in AgNP-treated cells, indicating the involvement of Bcl-2 in apoptosis. Conclusion: Overall, the fact that di-methyl flubendazole-based silver nanoparticles showed a novel and cost-effective natural antitumor and antibacterial agent.

In this study, silver nanoparticles were synthesized using Cucumis melo L. leaf extract via a green synthesis approach and their potential against diabetes and coccidiosis was tested under in vitro conditions. The phytochemical components in the leaf extract reacted with silver nitrate in solution and yielded C. melo-silver nanoparticles (Cm-AgNPs). The synthesis of AgNPs was confirmed via UV–visible spectroscopy by obtaining a peak at 440 nm. The nanoparticles were characterized by their morphology, crystallinity, and the presence of functional groups. In vitro α-amylase and α-glucosidase inhibition assays were carried out at different concentrations in the range of 20 to 100 μg/mL of Cm-AgNPs. The Cm-AgNPs exhibited enzyme inhibitory activity in a concentration-dependent manner. As the concentration of Cm-AgNPs increased the inhibitory activities were also increased linearly and the highest inhibition was observed at 100 μg/mL. The effectiveness of Cm-AgNPs against Eimeria tenalla was assessed by an in vitro 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay using Madin–Darby bovine kidney (MDBK) cell lines. The results revealed that the viability of the oocysts and further sporulation were decreased with the increased concentration of Cm-AgNPs. The AgNPs synthesized from the C. melo leaf extract have shown promising potential against diabetes and coccidiosis, and they could be used in biomedical applications.

The present study demonstrated microbial corrosion protection of MS 1010 on cooling tower water using plant-based inhibitors derived from methanolic extraction of dry mangrove leaves (R.mangle and A.marina), and its assessment of antibacterial activity against corrosive bacteria (B.megaterium) was investigated. FT-IR and GC–MS analyzed the inhibitors component and corrosion behavior of MS 1010 on cooling water, with and without inhibitors were analyzed by EIS and Tafel studies. GC–MS spectra confirmed the presence of Myo-Inositol, 4-C-methyl and chromene as major constituents presented on the R.mangle whereas Lupeol, trifluoroacetate and beta-amyrin compounds were found on the A.marina. In the cooling water, these two inhibitors demonstrated outstanding antibacterial activity and controlled biofilm growth. As plant-based inhibitors were used in cooling water systems, EIS data showed a significant increase in Rct value when compared to the control system. Tafel plot indicates inhibitors have mixed inhibitory effects and for the systems with and without inhibitors, the icorr value was 1.5649A and 2.0875A, respectively. At the optimal dose of 25 ppm, the inhibitory efficiency of MERM and MEAM was 81% and 80%, respectively. The overall discussion reveals that inhibitor substances can be absorbed on the metal surface and then act as a dual role in inhibiting corrosive bacterial growth and barrier to the corrosion process in the cooling water system.

We report the design of flexible, inexpensive, enduring, and efficient composite scintillation based on polystyrene (PS)/blue-emitting conjugated oligomer (CO)/ZnO nanoparticles. The oligomer utilized was 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (ADS086BE or BECV-DHF). Polystyrene was used as a matrix, and ZnO NPs were used as γ-ray stoppers. The formation of blends was analyzed using X-ray diffraction (XRD) and EDS. Field emission scanning electron microscopy (FE-SEM) images showed micron-sized bun (nearly square)-shaped domains, noodle-like structures, and submicron-sized domains with square-shaped nanosized domains for PS, PS/BECV-DHF, and PS/BECV-DHF/ZnO scintillator samples. The optical properties show that PS/BECV-DHF and PS/BECV-DHF/ZnO had absorption peaks at 350 and 375 nm and fluorescence peaks at 455 nm and 475 nm, respectively. The fabricated scintillators were coupled to the R6094 Hamamatsu Photomultiplier and gamma data acquisition system based on a multichannel analyzer (MCA). Gamma spectra were measured via three gamma-ray sources, Am-241, Cs-137 and Co-60. The results show better scintillation counting in the fabricated PS/BECV-DHF/ZnO than PS/BECV-DHF and the PS sample reference samples.

The M. citrifolia, commonly called starvation fruit, plays an essential role in daily dietary intakes, as it contains several vitamins, phytochemicals, and electrolytes. These constituents have several biological activities that are anti-tumor, antibacterial, antiviral, antifungal, and play a role in the immune system. The silver nanoparticles (AgNPs) were synthesized using a more uncomplicated and fast means using the M. citrifolia fruit samples. The Silver ions (Ag+) readily get reduced to (Ag0) to perform M. Citrifolia AgNPs hence the fruit extracts of M. Citrifolia can be considered potential lowering agents. The preliminary confirmation was done qualitatively by change of color into brownish-black, and the color change was observed due to bio-reduction and the Surface Plasmon Resonance (SPR) vibration. It was established by the absorbance peak at 430 nm using UV–Visible spectral analysis. Scanning Electron microscopy (SEM) showed the particle size ranging from 12 to 26 nm. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of the functional groups from synthesized M. citrifolia AgNPs. The biochemical studies were supported by the effect of antioxidant and anticancer properties of M. citrifolia AgNPs. The pathological changes were studied using hematoxylin, and Eosin staining in Albino mice, which was no tumor (Ehrlich ascites carcinoma) cell invasion exhibited in Fluorouracil treated group. The present investigation proves that the M. citrifolia fruit extract derived AgNPs is a promising antioxidant agent to treat liver cancer.

A novel biological approach is attempted to convert the human urinary waste into a well-designed bionanomaterial. In the present study, biological activated ammonia gas (NH3(g)) mediated synthesis of hydroxyapatite material (B-HAp) and then impregnation of silver nanoparticles (AgNPs) on the B-HAp material surface was performed by photoreduction method and was followed by an evaluation of its antibacterial activity and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. X-ray diffraction spectroscopy (XRD) and Field emission-scanning electron microscopy (FE-SEM) were engaged to analyze the synthesized materials. Analytical studies revealed the morphology of the crystalline B-HAp synthesized by biologically activated NH3(g) as spherical shaped with AgNPs impregnated on over it. Atomic Absorption Spectrometers (AAS) estimated 2–7 ppm of Ag+ ion were released from the 100 ppm of Ag concentration was impregnated with B-HAp material (B-HAp-Ag-10). It was also found to be an excellent performance of antibacterial activity against Pseudomonas sp, E.coli and S. aureus. The cell- material interaction study of the thus synthesised B-HAp-Ag-10 was found to exhibit a minimal cytotoxicity level when incorporated in MG63 osteosarcoma cell lines, thus confirming the prospective biological application of our material in the biomedical field.

Nanobiotechnology is an exuberant sphere of science that exhibits potential application in cancer therapy, targeted chemotherapy, molecular diagnosis and molecular imaging. Present investigation discloses green route synthesis of selenium nanoparticles leading to functionalization as anti leukemia nanomaterial. Emergence of resistance over cancer radiotherapy and chemotherapy is found to be the key factor behind the clinical treatment failure and recurrence. Selenium nanoparticles (SeNPs) with distinctive physicochemical features emerged as a novel nanocarrier and therapeutic agent with broad spectrum of medicinal properties. On the basis, biogenic technology has been proposed to synthesize selenium nanoparticles using Cassia auriculata and characterized using standard techniques. Newly synthesized selenium nanoparticles’ UV intense peak is achieved at 252 nm with crytalline surface morphology clear in SEM analysis. Cassia auriculata mediated selenium nanoparticles’ TEM analysis exhibits polydispersed with 10–20 nm. FTIR spectrum confirms the reduction of carboxyl group and capping of alkane group in Cassia auriculata synthesizes the selenium nanoparticles and its anti cancer potentiality has been explored by anti-leukemia activity using in vitro studies.

Two chromium resistant alkalophilic bacterial strains (CRAB), namely Bacillus cohnii SR2 and Bacillus licheniformis SR3 were isolated and identified from tannery effluent. Bioreduction of chromium (VI) into chromium (III) by CRAB was investigated in the present study. Optimization of process parameters with respect to bioreduction percentage was studied by Response Surface Methodology (RSM) software, v12. Both the strains were found to achieve highest chromium (VI) bioreduction of 94 and 95% in 100 mg/L at the end of 25 h at pH 9.0. At an optimized concentration of 550 mg/L, a maximum bioreduction of 82 and 90% by SR2 and SR3 was noted within 25 h. In addition, both the strains showed tolerance to chromium until 1000 mg/L. Scale-up studies using Air lift bioreactor system by CRAB with real tannery effluent showed 100% bioreduction within 8 h. Therefore, this study signified the astonishing bioreduction capability of CRAB isolates that was quite evident in scale-up studies too. Keywords: Alkalophilic, Bioreduction, Chromium resistant, Response surface methodology, Tannery effluent

The worldwide increase in malignancy rates has caused an increase of research interest for compelling and safe materials used for cancer treatment. A standout amongst the most pervasive types of treatment for malignant growth is photodynamic therapy (PDT), which is viewed as an alternative to radiotherapy and chemotherapy. PDT utilizing metal-based nanoparticles (NPs) is anticipated to be a useful approach for the treatment of malignant tumors. In the present study, NiO NPs were synthesized via a chemical co-precipitation (CPT) technique and characterized using XRD, SEM, TEM, UV–Visible spectroscopy, and EDX spectroscopy. The particle size was measured to be in the range of 90–120 nm using different characterization techniques. UV–visible spectroscopy showed the maximum absorption band was 340 nm, which confirmed the formation of the NiO NPs. Subsequently, the cytotoxicity of the NiO NPs was studied using a HeLa cancer cell line at various concentrations (10–180 μg/mL). An MTT assay was carried out and the reactive oxygen species (ROS) were investigated to determine the cell killing effects and their relationship with the loss of cell viability upon treatment with NiO alone or in the presence of light. Our results show that a light dose of 100 J/cm2 and NiO NPs concentration of 180 μg/mL exhibited an effective PDT outcome on cervical cancer cells. These key outcomes support the photokilling effect of NiO NPs as a potential treatment for cervical malignancy and their in-vivo application is inferred from their biocompatible properties. Keywords: NiO NPs, Cytotoxicity, ROS, Cellular morphology

Titanium alloys, particularly Ti6Al4V, are commonly used in biomedical applications. However, the inclusion of aluminum (Al) and vanadium (V) in this alloy can cause cytotoxic effects in the human body, resulting in Alzheimer’s disease and cancer. This study compares the performance of biocompatible alloys containing non-toxic elements, such as tin (Sn) and niobium (Nb), which are considered safe for implantation. Two sets of alloys were selected, Ti5Sn and Ti5Sn5Nb, and their properties were compared to Ti6Al4V. First, the alloys were prepared using a power metallurgical technique. Then, their phase analysis, hardness, wear resistance, strength, and corrosion performance in simulated body fluid (SBF) solution were characterized. Optical microscopy was used to study the microstructure, XRD was used to identify phases, and electrochemical testing was conducted to assess the alloys’ anodic and cathodic characteristics. Nanoindentation techniques were used to analyze surface characteristics, such as elastic modulus, nano hardness, and wear resistance. The results showed the alloys containing Nb and Sn had lower corrosion rates in SBF solution compared to Al-containing alloys. Moreover, Nb-containing alloys exhibited the highest hardness, 72% higher than Al-containing alloys. The corrosion-resistant properties of the alloys containing Nb and Sn were higher than those without Nb or Sn, suggesting they may be ideal for orthopedic implants in humans.

Objective: Alternative medicine plays an important role today in searching for therapeutics for cancer and viral infection. So, a scientific validation to characterize constituents in the alternative medicines and therapeutic testing is warranted using modern instrumentation. Methods: In the present study, an old herbomineral formulation, KanthaRasavillai [KRV], was characterized using UV–vis spectrometry, FT-IR, XRD, SEM, and TEM study. Also, In vitro and in vivo studies were done to evaluate their antiviral and anticancer activity. FT-IR and XRD studies revealed a cocktail of nanoparticles of mercury, magnetic oxide, cinnabar, and arsenic.Results.Based on SEM, TEM, and XRD report, KRV contains nanoparticles in the size range of 9.1 nm to 25.0 nm. FT-IR analysis exposed the presence of several anti-cancerous bioactive compounds.Further in vitro testing against HCV virus proved KRV to inhibit HCV virus a close relative to SARS-CoV-2. MTT assay confirmed the anticancer effect of KRV against Huh-7 and MCF-7 cell lines. Conclusion: The anticancer and antiviral properties in the ancient herbomineral drug with a cocktail of metal nanoparticles acknowledge the traditional medical practice as a pioneering approach for present-day ailments. However, the study concludes that the use of KRV depends on safety dosage and genuine preparation as described by ancient saints.

The natural product Catharanthus roseus and Lawsonia inermis leaf extract enhancement in the anti-corrosion potential green corrosion inhibitor (GIC) for Bacillus oleronius EN9 biofilm forms on mild steel (MS) in re-circulating water environment is demonstrated. This re-circulating water was enhancing the corrosion due to the temperature, pH, salinity, and chloride. Therefore, we need to improve the performance of the inhibitors. The chosen GIC inhibition was examined by antibacterial assay, weight loss, surface, and electrochemical analysis. L. inermis has shown the antibacterial activity (75%) against the corrosive bacteria Bacillus oleronius than the C. roseus (44%) optimum concentration of 20 ppm. L. inermis was selected for further studies and it reduces the corrosion rate up to 75 % in the 1% NaCl system. Scanning electron microscopy confirms the formation of the protective film on MS and GC–MS confirmed the presence of complex molecules of L. inermis. Therefore, the current work concluded that green corrosion inhibitor is suitable for the inhibition of biocorrosion of MS in the re-circulating system and a promising alternative for chemical inhibitor.

Carob-mediated calcium hydroxide nanoparticles (C-CaOH2 NPs) are a type of NPs, newly developed via a green synthesis method, that have demonstrated good in vitro biocompatibility. However, their antibacterial potential has not yet been explored. Both calcium hydroxide and carob are known for their antibacterial potency as bulk materials; thus, we hypothesized that C-CaOH2 NPs may exhibit promising antibacterial efficacy. This study aimed to examine the antibacterial activity of C-CaOH2 NPs against aerobic and anaerobic strains using zone of inhibition (ZOI), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) tests. The results showed that the Gram-negative aerobic strains are more susceptible than the Gram-positive stains. The most susceptible bacteria were P. aeruginosa, E. coli, and S. aureus, in that order. Conversely, P. micra and E. faecalis were the least susceptible strains. The best recorded ZOIs were at 100 and 150 mg/mL concentrations in all bacteria, with the greatest diameter (11.7 ± 0.6 mm) exhibited in P. aeruginosa. Moreover, the MICs for aerobes were 3.12 mg/mL, except for E. faecalis (0.78 mg/mL) and K. pneumoniae (1.56 mg/mL). MBCs were 12.5 mg/mL for all except P. aeruginosa (3.12 mg/mL) and K. pneumoniae (6.25 mg/mL). The anaerobic strain P. micra exhibited the highest values for both MIC (15.62 mg/mL) and MBC (31.25 mg/mL). The current investigation revealed that C-CaOH2 NPs have intermediate and dose-dependent antibacterial activity that may have variable biomedical applications.

Herein, nanorods-like ZnO particles was prepared by effective chemical synthesis process and carbon nanoplates supported ZnO nanorods (ZnO/C) was prepared by wet chemical process. The synthesized materials were characterized by various instrumental analysis via power XRD, UV–vis DRS, FESEM and EDX spectroscopy. The synthesized samples were utilized as competent photocatalysts for the remediation wastewater. The visible light-driven photocatalytic performances of the samples was assessed by the photodegradation of methylene blue. Compared to pure ZnO, the ZnO/C photocatalyst showed an excellent photocatalytic performances by efficiently degrading (around 95%) of MB as targeted organic pollutants within the irradiation time period of 80 min. The improved photodegradation activity of ZnO/C might be due to an improved absorption of ZnO/C photocatalyst in the visible region as well as good structural morphology and surface state which was accredited to an efficient separation of charge carriers and hindered recombination at ZnO/C interfaces. The higher photo-stability and photocatalytic performance was exposed that ZnO/C samples can be a potential photocatalysts for the applications of environmental remediation. Finally, a plausible degradation pathway mechanism for an enhanced activity of ZnO/C has been proposed. Keywords: Methylene blue, Photocatalysis, Photodegradation, Radicals trapping, Visible light, ZnO/carbon nanoplates

Background: Hemoglobinopathies (HgP) are prevalent in certain regions of the world. The World Health Organization estimated that 5% of the world’s population is a carrier of the potentially pathological hemoglobin (Hb) gene. Methods: This study aimed to compare the performance of fluorescence spectroscopy, a simple and inexpensive method, with that of conventional techniques for diagnosing thalassemia. The red blood cell (RBC) counts and levels of Hb, HbA, HbA2, and HbS were estimated via conventional methods of complete blood count and Hb electrophoresis to diagnose thalassemia. Results: The RBCs and Hb, particularly the average values of HbA and HbA2, were lower in patients with thalassemia than in the normal controls. These hematologic parameters were also analyzed via fluorescence spectroscopybased on fluorescent biomolecules including tyrosine (275 nm), tryptophan (290 nm), nicotinamide adenine dinucleotide (NADH) (370 nm), flavin adenine dinucleotide (FAD) (450 nm), and porphyrin (585–635 nm). In thalassemia patients, all these parameters were above the normal range, primarily due to abnormal depression of NADH and elevation of FAD. Conclusion: Thalassemia canbe diagnosed via a fluorescent spectral method with an accuracy of 85% for blinded groups. This method may be useful for screening patients and reducing the cost of diagnosis in many rural countries. Keywords: Thalassemia, Spectral methods, Fluorescent biomolecules, Conventional methods

Herein, sponge-like bismuthoxychloride (BiOCl) and hematite iron oxide (α-Fe2O3) were synthesized by simple and inexpensive method via two-step process, including hydrothermal and solution combustion method. The BiOCl/α-Fe2O3 composite photocatalysts were prepared by incorporating various weight ratios of α-Fe2O3 on BiOCl by a low-cost wet chemical process. The chemical interaction, phase and crystalline nature of the samples were ascertained by Fourier transform infrared spectroscopy (FT-IR) and x-ray diffraction (XRD). Further, the surface morphology and optical properties of the fabricated materials was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–vis diffuse reflection spectroscopy (DRS). Photocatalytic activities of the fabricated samples towards the photocatalytic degradation of direct red 81 (DR81) was evaluated under ultraviolet light illumination. The BiOCl/α-Fe2O3 composites showed remarkably enhanced photo-induced catalytic performances. The photocatalyst with optimal content of α-Fe2O3 with the highest photocatalytic performance was observed to 1%-BiOCl/α-Fe2O3. The synergistic improvement in the photodegradation of BiOCl/α-Fe2O3 sample may be because of an expansion in the noticeable light absorption efficiency as well as fast photo-generated charge separation. A probable mechanism for the photocatalytic degradation has been proposed for the catalytic performance of BiOCl/α-Fe2O3 photocatalyst. Keywords: Bismuthoxychloride, Direct red 81, Iron oxide, Photocatalysis, Photodegradation

The improvement of optical and optoelectronic properties of the individual poly [2-methoxy-5- (2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), poly[2-methoxy-5-(3,7-dimethyl-octyloxy)-1,4-phenylenevinylene]–End capped with Dimethyl phenyl (OC1C10–PPV–DMP), and poly (9,9′-di- n -octylfluorenyl-2,7-diyl) (F8) was revealed by blending them in ternary hybrid with optimal ratio (F8/2 wt.% MEH-PPV/2 wt.% OC1C10–PPV–DMP). All individual and optimal ternary solutions were prepared via the solution-blending method followed by depositing them onto glass and ITO substrates using spin-coating technique. The semi-crystalline phase of the ternary hybrid and the strong mixing between the conjugated polymers were evidenced by observing the X-ray diffraction patterns that related to F8 into the hybrid diffractogram. The optical and optoelectronic properties of all prepared thin films were investigated in terms of absorption and emission spectra, Commission International d′Eclairage (CIE) coordinates, and current–voltage (I-V) characterizations. Emission peaks at the entire range of visible spectrum can be revealed from the ternary hybrid of the three individual conjugated polymers, producing white emission as evidenced from the emission spectrum and CIE coordinates of the hybrid. Among all fabricated organic light-emitting diodes (OLEDs) devices, the ternary hybrid-based-OLED revealed the best performance in terms of current and turn-on voltage.

Objective: Absorption spectroscopy and calorimetry has been a very convenient tool in the diagnosis of a variety of diseases. In recent times, fluorescence emission spectroscopy is proposed to be a more sensitive technique for disease detection. Methods: In this context, fluorescence emission spectra have been obtained from blood and urine samples from clinically suspected subjects of cancer (N = 40) as compared with normal control samples. Results: Based on a certain set of fluorometric ratio parameters the samples of suspected subjects were scored positive or negative to assess the validity of the spectral technique in detecting cancer, irrespective of organ or stage. This study was done in the premises of a hospital with the blinded sets of blood and urine samples and it has classified correctly 30 out of 40 (75% true positive) indicating a reasonable level of accuracy of this new, simple technique Conclusion: It could be of significant value as the first-line defense in the screening process of any cancer.

In this investigation, we have analyzed the structural, electrical, and optical behaviors of pure and composite thin films which are obtained from 2D monolayer molybdenum disulfide (MoS2) flakes, conjugated oligomer (CO) 1,4-Bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF), and by combining CO (BECV-DHF) with MoS2 in forms of CO/MoS2 composites. All the samples are coated on SiO2/Si substrates using the spin coating procedure where a spin-coating solution has been obtained by dispersing CO and MoS2 in ethanol or toluene. The structural morphology of MoS2 films and CO/MoS2 films of various thicknesses are analyzed using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), and profilometer. These experimental results confirm the formation of MoS2 layer composite with oligomer nanocrystals. The optical properties of MoS2, CO, and CO/MoS2 films showed that the increased film thickness shifted the spectral peaks towards near infrared (NIR) and ultraviolet–visible (UV) regions of the electromagnetic spectrum. Moreover, devices such as solar cells, flexible memory cell and MOSFET were designed. The I-V characteristics of these devices show that CO/MoS2 composite films could serve as potential candidates for organic-inorganic nano-electronic device applications.

The current work reports the biosynthesis of silver nanoparticles (AgNPs) using the antimicrobial activities of ethyl acetate extract of Urtica diocia (UD) leaves as a reducing and capping agent. The synthesized UD-AgNPs were characterized using UV–visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDAX), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and dynamic light scattering (DLS). The UD-AgNPs were evaluated against Gram-positive and Gram-negative bacteria, and their size, shape, and distribution were recorded. The average size of an NP was 19.401 nm. The zone of inhibition (ZOI) for 75 µL of UD-AgNPs against Pseudomonas aeruginosa (P. aeruginosa) was 21 ± 0.4 mm more than that of the control drug Ciprofloxacin (16 ± 10 mm). The minimum inhibitory concentration (MIC) was the lowest against Escherichia coli (E. coli) (36 ± 3 µg/mL) and Staphylococcusepidermidis (S. epidermidis) (38 ± 3 µg/mL). Moreover, the minimum bactericidal concentration (MBC) was the lowest against E.coli (75 ± 00 µg/mL) and Enterococcus faecalis (E. faecalis (83 ± 16 µg/mL). Thus, the UD-AgNPs synthesized using the ethyl acetate extract of UD can be used as a new antimicrobial drug.

The tuning of photophysical properties of the poly[2-methoxy-5-(3,7-dimethyl-octyloxy)-1,4-phenylenevinylene]—end capped with dimethylphenyl (DMP), MDMO-PPV–DMP, was achieved by incorporation of ZnO NPs with various contents. Hybrid nanocomposites of MDMO-PPV–DMP with ZnO NPs were prepared by solution blending method and then deposited onto glass substrates. The structural properties of the hybrid nanocomposites samples were characterized using X-ray diffraction, FTIR, and FE-SEM, while their optical properties were extracted from the absorption and photoluminescence spectra. The energy band gap, energy tail, steepness parameter, and CIE chromatic coordinates were tuned by increase the content of ZnO NPs into the polymer matrix. The ZnO NPs incorporation assists the emission wavelength shift and multicolor emitting from the hybrid nanocomposites.

Quinoline Schiff bases display potential applications in optoelectronics and laser fields because of their unique optical properties that arise from extensive delocalization of the electron cloud, and a high order of non-linearity. In this context, a new class of conjugated quinoline-derivative viz. N-(quinolin-3-ylmethylene)anilines were synthesized from 2-hydroxyquinoline-3-carbaldehyde in two good yielding steps. The ability of these imines to accept an electron from a donor is denoted by their electron acceptor number and sites, which is calculated using density functional theory (DFT). The optical properties such as FT-IR, Raman, UV-VIS, and EDS spectra were calculated using TD-DFT, which also provided the energy gap, HOMO-LUMO structure. The optical properties of the synthesized imino quinolines were experimentally studied using photoluminescence and absorption spectroscopy. The properties such as Stokes shift and quantum yield were calculated using experimental data. Furthermore, the compound bearing a methyl group on the aryl ring and ZnO nanoparticles (hydrothermally synthesized) were dissolved in toluene, and optically excited with a 355 nm nanosecond laser, which produced a random laser.

Tuning the emission spectrum of both binary hybrids of poly (9,9′-di-n-octylfluorenyl-2,7-diyl) (PFO) with each poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly[2-methoxy-5-(3,7-dimethyl-octyloxy)-1,4-phenylenevinylene] end-capped with Dimethyl phenyl (MDMO-PPV–DMP) by a systematic doping strategy was achieved. Both binary hybrid thin films of PFO/MEH-PPV and PFO/MDMO-PPV–DMP with various weight ratios were prepared via solution blending method prior to spin coating onto the glass substrates. The conjugation length of the PFO was tuned upon addition of acceptors (MEH-PPV or MDMO-PPV–DMP), as proved from shifting the emission and absorption peaks of the binary hybrids toward the acceptor in addition to enhancing the acceptor emission and reducing the absorbance of the PFO. Förster resonance energy transfer (FRET) is more efficient in the binary hybrid of PFO/MDMO-PPV–DMP than in the PFO/MEH-PPV. The efficient FRET in both hybrid thin films played the major role for controlling their emission and producing white emission from optimum ratio of both binary hybrids. Moreover, the tuning of the emission color can be attributed to the cascade of energy transfer from PFO to MEH-PPV, and then to MDMO-PPV–DMP.

New double perovskite oxides A2YVO6 (A = Mg, Sr) were prepared and synthesized using conventional methods via a solid-state reaction route. The samples were studied by X-ray powder diffraction (XRD) and the prepared Mg2YVO6 and Sr2YVO6 samples were shown to have monoclinic crystal structures belonging to the (P2/m) space group. The crystallite size in the samples was found to decrease from 56.320 to 40.480 nm upon increasing the A-site ionic radius. Scanning electron microscopy (SEM) results demonstrated that the sample microstructure consisted of homogenous crystallites of approximately 6.5-µm in size, and energy-dispersive X-ray (EDX) results revealed elements ratios in samples that were identical to the expected values. FTIR results allowed the identification of particular perovskite structural features from vibrational peaks in the range of 400–4000 cm−1, and optical structure in the range of 190–600 nm was obtained from ultraviolet–visible (UV–vis) spectroscopy. The identity of the element at the A site was found to affect the band-gap energy, which decreased from 2.9 to 2.4 eV with the change from Mg2YVO6 to Sr2YVO6, indicating that the A2YVO6 (A = Mg, Sr) samples may possess insulating characteristics.

The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs).

Ba2−xSrxZnWO6 double perovskite (DP) oxide compounds (x = 1, 1.25, 1.5, 1.75, 2) were successfully created by means of conventional solid-state techniques. The crystal structures of our series were studied using an X-ray diffractometer. The x = 1 compound has a cubic (Fm-3m) crystal structure, the 1 ≤ x ≤ 2 compounds have tetragonal (I4/m) symmetry, and the phase was transferred to monoclinic (P21/n) symmetry for the Sr2ZnWO6 (x = 2) compound. Scanning electron microscopy (SEM) was used to investigate the morphology of the series, showing that the samples had crystallized microstructures. Molecular bonds were investigated using Fourier transform infrared and Raman spectroscopies, which confirmed the double perovskite octahedral geometry for the samples in our series. Furthermore, the octahedral W–O6 anti-symmetric stretching mode was found to occur. The optical properties of the Ba2−xSrxZnWO6 series were studied using Ultraviolet–visible (UV–vis) diffuse reflectance and photoluminescence (PL) spectroscopies. The absorption edge of the samples appeared around the near-violet and visible spectra, between 336–360 nm. The band gap energy was investigated in two ways—using the absorption cutoff and Tauc plots—which increased from 3.52 to 3.7 eV with increasing substitution of Ba2+ by Sr2+. Furthermore, excitation and emission spectra were collected at room temperature. A broad band at 260–360 nm appeared in the PLE spectra for all samples, and the PL spectra of the samples had a band that spread from 320–450 nm.

Active nanoplasmonics have recently led to the emergence of many promising applications. One of them is the spaser (surface plasmons amplification by stimulated emission of radiation) that has been shown to generate coherent and intense fields of selected surface plasmon modes that are strongly localized in the nanoscale. We propose a novel nanospaser composed of a metal nanoparticles-graphene nanodisks hybrid plasmonic system as its resonator and a quantum dots cascade stack as its gain medium. We derive the plasmonic fields induced by pulsed excitation through the use of the effective medium theory. Based on the density matrix approach and by solving the Lindblad quantum master equation, we analyze the ultrafast dynamics of the spaser associated with coherent amplified plasmonic fields. The intensity of the plasmonic field is significantly affected by the width of the metallic contact and the time duration of the laser pulse used to launch the surface plasmons. The proposed nanospaser shows an extremely low spasing threshold and operates in the mid-infrared region that has received much attention due to its wide biomedical, chemical and telecommunication applications.

Scattering (Rayleigh and Raman) and fluorescence are two common light signals that frequently occur together, confusing the researchers and graduate students experimenting in molecular spectroscopy laboratories. This report is a brief study presenting a clear discrimination between the two signals mentioned, employing a common spectrofluorometer such as the PerkinElmer LS 55. Even better, the resonance Raman signal of a molecule (e.g., acetone) can be obtained elegantly using the same instrument.

Hybrid nanocomposites can provide a promising platform for integrated optics. Optical nonlinearity can significantly widen the range of applications of such structures. In the present paper, a theoretical investigation is carried out by solving the density matrix equations derived for a metal nanoparticles-graphene nanodisks-quantum dots hybrid system interacting with weak probe and strong control fields, in the steady state. We derive analytical expressions for linear and third-order nonlinear susceptibilities of the probe field. A giant self-Kerr nonlinear index of refraction is obtained in the optical region with relatively low light intensity. The optical absorption spectrum of the system demonstrates electromagnetically induced transparency and amplification without population inversion in the linear optical response arising from the negative real part of the polarizabilities for the plasmonic components at the energy of the localized surface plasmon resonance of the graphene nanodisks induced by the probe field. We find that the self-Kerr nonlinear optical properties of the system can be controlled by the geometrical features of the system, the size of metal nanoparticles and the strength of the control field. The controllable self-Kerr nonlinearities of hybrid nanocomposites can be employed in many interesting applications of modern integrated optics devices allowing for high nonlinearity with relatively low light intensity.

Nanostructured materials are promising compounds that offer new opportunities as sensing platforms for the detection of biomolecules. Having micrometer-scale length and nanometer-scale diameters, nanomaterials can be manipulated with current nanofabrication methods, as well as self-assembly techniques, to fabricate nanoscale bio-sensing devices. Nanostructured materials possess extraordinary physical, mechanical, electrical, thermal and multifunctional properties. Such unique properties advocate their use as biomimetic membranes to immobilize and modify biomolecules on the surface of nanoparticles. Alignment, uniform dispersion, selective growth and diameter control are general parameters which play critical roles in the successful integration of nanostructures for the fabrication of bioelectronic sensing devices. In this review, we focus on different types and aspects of nanomaterials, including their synthesis, properties, conjugation with biomolecules and their application in the construction of immunosensing devices. Some key results from each cited article are summarized by relating the concept and mechanism behind each sensor, experimental conditions and the behavior of the sensor under different conditions, etc. The variety of nanomaterial-based bioelectronic devices exhibiting novel functions proves the unique properties of nanomaterials in such sensing devices, which will surely continue to expand in the future. Such nanomaterial based devices are expected to have a major impact in clinical immunodiagnostics, environmental monitoring, security surveillance and for ensuring food safety.

Tunable lasers are essential for medical, engineering and basic science research studies. Most conventional solid-state lasers are capable of producing a few million laser shots, but limited to specific wavelengths, which are bulky and very expensive. Dye lasers are continuously tunable, but exhibit very poor chemical stability. As new tunable, efficient lasers are always in demand, one such laser is designed with various sized CdSe/ZnS quantum dots. They were used as a colloid in tetrahydrofuran to produce a fluorescent broadband emission from 520 nm to 630 nm. The second (532 nm) and/or third harmonic (355 nm) of the Nd:YAG laser (10 ns, 10 Hz) were used together as the pump source. In this study, different sized quantum dots were independently optically pumped to produce amplified spontaneous emission (ASE) with 4 nm to 7 nm of full width at half-maximum (FWHM), when the pump power and focusing were carefully optimized. The beam was directional with a 7 mrad divergence. Subsequently, these quantum dots were combined together, and the solution was placed in a resonator cavity to obtain a laser with a spectral width of 1 nm and tunable from 510 to 630 nm, with a conversion efficiency of about 0.1%.