Se NPs Research Articles

Optical, structural, and electrical conductivity of PEO/chitosan incorporated by Se NPs produced by one-potential laser ablation

Optical, structural, and electrical conductivity of PEO/chitosan incorporated by Se NPs produced by one-potential laser ablation

A comprehensive study of selenium and cerium oxide nanoparticles on mung bean: Individual and synergistic effect on photosynthesis pigments, antioxidants, and dry matter accumulation

In this study, the interaction effects of CeO2 NPs (250, 500 and 1000 mg L−1) and Se NPs (25, 50 and 75 mg L−1) were evaluated in mung bean (Vigna radiata). Single NPs and their combinations were foliar applied to 45-day old mung bean plants under greenhouse conditions. In each pot, a total volume of 100 mL of NPs suspension was sprayed on the plants shoot in two steps and one-week interval. After 94 days of growth, membrane degradation, antioxidant activity, photosynthetic pigments, and dry matter accumulation were assessed. At 250 and 500 mg CeO2-NPs L−1, there was partial increase of dry matter, stimulated activity of antioxidant enzymes (p ≤ 0.05), and reactive oxygen species (ROS). However, at 1000 mg L−1, CeO2-NPs caused strong accumulation of ROS (p ≤ 0.05), enlargement of starch granules and swelling of chloroplasts. In addition, at such concentration, there was accumulation of starch granules, reduction of photosynthetic pigments, biological nitrogen fixation, chlorosis, and a significant retardation in plant growth, compared with control, (p ≤ 0.05). Combination of Se-NPs (25 and 50 mg L−1) with 250 mg L−1 of CeO2 NPs decreased hydrogen peroxide, improved CAT, Chla, Chlb, and increased dry matter (p ≤ 0.05). At 1000 mg CeO2 NPs L−1, foliar spray of Se-NPs led to Ce accumulation in the cell wall and increased levels of SOD and proline (p ≤ 0.05). Results showed that 25 and 50 mg Se NPs L−1 ameliorate the stress of CeO2 NPs by upregulating photosynthesis pigments, antioxidants, and dry matter accumulation. Therefore, depending on the CeO2 NPs concentration, the mechanisms of Se NPs in modulating CeO2 NPs stress varied; low concentrations of Se NPs may strengthen the metabolism of legumes, and protect them against foliar toxicity of CeO2 NPs in semi-arid ecosystems.

Selenium nanoparticles with boron salt-based compound act synergistically against the brown-rot Serpula lacrymans

The spherical polyvinylpyrrolidone (PVP) stabilized red Se NPs (PVP–Se NPs) with a mean size of ∼45 nm were prepared via upgraded one-step wet chemical reduction by L-cysteine, which considerably shortened the synthesis procedure. Their morphological features were characterized by high-resolution scanning transmission electron microscopy, UV-VIS spectroscopy, and small-angle X-ray scattering method. The toxicological properties of PVP-Se NPs were analyzed by colorimetric cell viability assay based on the reduction of a yellow tetrazolium salt (XTT) in mitochondria, a further assay based on the measurement of lactate dehydrogenase (LDH) release from damaged cell membrane, and finally by cell proliferation assay. The antifungal effect of PVP-Se NPs alone, or in a mixture of commercial fungicide containing 2% of boric acid, 2% alkylbenzyldimethylammonium chloride, and ∼0.9% ethanolamine in distilled water was tested on the brown-rot fungus Serpula lacrymans The fungus belongs to important basidiomycetes causing economically significant decay of wood, mainly in houses and particularly cold soil cellars. The average mass loss tests performed on spruce wood blocks after four months of inoculation with S. lacrymans showed an enhanced antifungal effect of the mixture of PVP-Se NPs with a commercial fungicide than a PVP-Se NPs or commercial fungicide alone, which proved their synergistic effect on inhibiting fungi growth. Finally, scanning electron microscopy analysis of outer and inner parts of wood blocks treated with our novel mixture was performed.

In vitro cytotoxicity, macromolecular interaction and antioxidant potential of dual coated selenium nanoparticles.

The present research focuses on synthesizing selenium nanoparticles (Se NPs) coated with Methionine and Folic acid. selenium-methionine-folate nanoparticles (Se-Met-Fa NPs) were prepared by the chemical precipitation method. These were characterized by UV-Vis spectroscopy, FTIR, X-ray diffraction, Zeta potential, ICP-AES, TEM, and Raman spectroscopy. The average diameter of nanoparticles was determined by TEM was 50 nm. In Vitro viability of cells exposed to Se-Met-Fa NPs were studied using MTT and AO/EB assay. Approximately 80% of cells were viable at 100 μg/ml concentration after 24 h of incubation, suggestive of the safety of nanoparticles. Macromolecular interaction studies were carried out with plasmid DNA and Bovine serum albumin (BSA) protein. UV-Vis Spectroscopy showed ground state complex formation of Se-Met-Fa NPs with BSA. Intrinsic fluorescence of BSA was quenched by Se-met-Fa NPs via Static quenching and was observed under Spectro-fluorimetry. Conformational structural change in α-Helices of BSA was observed to be 4.4% after the interaction with Se-Met-Fa NPs, and it was studied using CD spectroscopy. At 250 μg/ml Se-Met-Fa NPs prevented oxidative damage of Plasmid DNA. The total antioxidant property of Se-Met-Fa NPs expressed in terms of scavenging of free DPPH radicals. Ten micrograms per milliliter could inhibit 41% of DPPH, proving its scavenger role at the lowest concentration. Nanoparticles comprising antioxidant semi-conducting cores and encapsulated by biomaterials that are highly bioavailable can be promising therapeutic agents for inflammation and oxidative stress disorders studies.

Chiral Fe x Cu y Se nanoparticles as peroxidase mimics for colorimetric detection of 3, 4-dihydroxy-phenylalanine enantiomers

L-3,4-dihydroxy-phenylalanine (L-dopa) is the most widely used drug in Parkinson’s disease treatment. However, development of cost-effective and high-throughput sensors to accurate enantioselective discrimination of L-dopa and D-dopa remains challenging to date. Herein, on the basis of the peroxidase-mimic activity of chiral Fe x Cu y Se nanoparticles, we demonstrated a novel colorimetric sensor for determination of chiral dopa. The surface chiral ligand, L/D-histidine (L/D-His), endowed the nanozymes with enantioselectivity in catalyzing the oxidation of dopa enantiomers. According to the values of k cat/K m, the efficiency of L-His modified nanoparticles (L-Fe x Cu y Se NPs) towards L-dopa was 1.56 times higher than that of D-dopa. While, D-His can facilely reverse the preference of the nanozyme to D-dopa. On the basis of high catalytic activity and enantioselectivity of L-Fe x Cu y Se NPs in oxidation of L-dopa, the L-Fe x Cu y Se NPs-based system can be utilized for detection of L-dopa. The linear ranges for L-dopa determination were 5 μM–0.125 mM and 0.125 mM–1 mM with a detection limit of 1.02 μM. Critically, the developed sensor has been successfully applied in the quality control of clinical used L-dopa tablets. Our work sheds light on developing simple and sensitive chiral nanomaterials-based sensors for drug analysis.

Induction of Selenium Nanoparticles Disturbs Behavior, Blood and Serum Biomarkers and Oxidative Stress Markers from Vital Organs of Male and Female Albino Mice

Current investigation was focused to determine the biological effects of Selenium nanoparticles (Se NPs) in mice. Se NPs (50mg/ml saline/Kg body weight) were intraperitoneally injected to 5 week old albino mice (N = 22) for 14 days. Control group was intraperitoneally injected with saline water (N = 22). In all subjects, a series of neurological tests, hematological parameters and markers of oxidative stress in vital organs were determined. We are reporting that rota rod and open field test performance remained unaffected in Se NPs injected mice when compared with saline treated controls. Male mice injected with Se NPs had significantly less line crossing (P = 0.02) while performing light dark box. They approached object A less frequently (P = 0.02) and spent lesser time with it (P = 0.001) during novel object recognition test (trial 1). % lymphocytes were significantly reduced (P = 0.03) in these mice while % monocytes were higher than control (P = 0.03). Concentration of cholesterol (P = 0.02) and LDL (P = 0.003) was significantly decreased in male mice. Female Se NPs treated mice spent less time (P = 0.05) with B object in trial 1 and 2 (P = 0.04) of novel object recognition test. They had significantly reduced cholesterol level (P = 0.02) and significantly increased catalase activity in the liver (P = 0.01) than control. Remaining parameters of behavior, blood chemistry and markers of oxidative stress from vital organs were non-significantly different upon their comparison between Se NPs and saline injected mice.

Cefotaxime incorporated bimetallic silver-selenium nanoparticles: promising antimicrobial synergism, antibiofilm activity, and bacterial membrane leakage reaction mechanism.

In this research, we reported for the first time the simple incorporation of antibiotic cefotaxime (CFM) with the synthesized Ag NPs, Se NPs, and bimetallic Ag–Se NPs by gamma rays, as a promising cost-effective, and eco-friendly method. The synthesized nanocomposites were characterized by UV-Vis. spectroscopy, XRD, EDX, HR-TEM, SEM/mapping, and EDX studies. The antimicrobial synergistic potential was investigated after CFM drug incorporation. Antibiofilm activity, growth curve assay, and effect of UV illumination were examined against some pathogenic microbes. The antibacterial reaction mechanism was evaluated by protein leakage assay and SEM imaging. HRTEM imaging confirmed the spherical shape and an average diameter of 10.95, 20.54, and 12.69 nm for Ag NPs, Se NPs, and Ag–Se NPs, respectively. Ag NPs-CFM, Se NPs-CFM, and Ag–Se NPs-CFM possessed antimicrobial activity against Staphylococcus aureus (40, 42, and 43 mm ZOI, respectively), Escherichia coli (33, 35, and 34 mm ZOI, respectively) and Candida albicans (25, 22, and 23 mm ZOI, respectively). CFM-incorporated Ag–Se NPs were able to inhibit biofilm formation of S. aureus (96.09%), E. coli (98.32%), and C. albicans (95.93%). Based on the promising results, the synthesized nanocomposites showed superior antimicrobial potential at low concentrations and continued-phase durability; they may find use in pharmaceutical, and biomedical applications.

RGD Peptide-Conjugated Selenium Nanocomposite Inhibits Human Glioma Growth by Triggering Mitochondrial Dysfunction and ROS-Dependent MAPKs Activation

Chemotherapy is still one of the most common ways to treat human glioblastoma in clinic. However, severe side effects limited its clinic application. Design of cancer-targeted drugs with high efficiency and low side effect is urgently needed. Herein, silver nanoparticles (Ag NPs) and nano-selenium (Se NPs) conjugated with RGD peptides (Ag@Se@RGD NPs) to target integrin high-expressed glioma were designed. The results found that Ag@Se@RGD NPs displayed stable particle size and morphology in physiological condition, and induced significant integrin-targeted intracellular uptake. Ag@Se@RGD NPs in vitro dose-dependently inhibited U251 human glioma cells growth by induction of cells apoptosis through triggering the loss of mitochondrial membrane potential, overproduction of reactive oxygen species (ROS), and MAPKs activation. However, ROS inhibition dramatically attenuated Ag@Se@RGD NPs-induced MAPKs activation, indicating the significant role of ROS as an early apoptotic event. Importantly, Ag@Se@RGD NPs administration in vivov effectively inhibited U251 tumor xenografts growth by induction of apoptosis through regulation MAPKs activation. Taken together, our findings validated the rational design that Ag-Se NPs conjugated with RGD peptides was a promising strategy to combat human glioma by induction of apoptosis through triggering mitochondrial dysfunction and ROS-dependent MAPKs activation.

Synthesis of Nanocomposites of V₂OO5©Selenium Nanoparticles and Multiwalled Carbon Nanotubes for Antimicrobial Activity.

The authors report the preparation of the nanocomposite comprising of vanadium pentoxide (V₂O5) and selenium (Se) nanoparticles and functionalized multiwalled carbon nanotubes (MWCNTs) (V₂O5@Se NPs/MWCNTs). Since Se NPs possesses extraordinary physicochemical properties including larger surface area with higher adsorption capacity, V₂O5 NPs were adsorbed onto Se NPs surface through physisorption process (designated as V₂O5@Se NPs). The nanocomposite synthesized hydrothermally was evaluated for its antimicrobial activity. The morphology and microstructure of the nanocomposite were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, respectively. Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy (UV-Vis) were employed to analyze the spectral properties of nanocomposite. The microbicidal efficacy of nanocomposite was tested against Gram-negative (G-)ZGram-positive (G+) bacteria and fungus. This is the first report on the synthesis of V₂O5@Se NPs/MWCNTs nanocomposites by chemical method that showed microbicidal effect on micro-organisms. The thiol (-SH) units facilitates the enrichment of V₂O5@Se NPs onto MWCNTs surface. Ultimately, it reflects on the significant antimicrobial activity of V₂O5@Se NPs/MWCNTs.

Tailored Chiral Copper Selenide Nanochannels for Ultrasensitive Enantioselective Recognition and Detection.

We constructed a tailorable membrane channel system consisting of penicillamine molecules intercalated in copper selenide nanoparticles (Cu2-x Se NPs), which exhibited circular dichroism (CD) bands in the near infrared region (CD, 800-1600 nm) with a maximum intensity of 164.5 mdeg at 1440 nm. The chiral ligand hybridized to the surface of achiral Cu2-x Se NPs by breaking the intrinsic symmetry of Cu2-x Se NPs and further large-scale assembly induced strong optical activity. The fabricated multilayer chiral membrane achieved an increased rectification ratio (RR) up to 114. The integration of penicillamine allowed for high enantioselective recognition against naproxen,which displayed high sensitivity with a limit of detection (LOD) as low as 0.027 nM.

Protective effect of starch-stabilized selenium nanoparticles against melamine-induced hepato-renal toxicity in male albino rats

Melamine and its analogues are illegally added to raise the apparent protein content in foods. The elevated concentrations of these compounds cause adverse effects in humans and animals. In this contribution, the protective effects of the synthesized starch-stabilized selenium nanoparticles (Se-NPs@starch) on melamine-induced hepato-renal toxicity have been systematically investigated. The Se-NPs@starch were characterized by X-ray photoelectron spectroscopy (XPS) analysis, energy dispersive spectroscopy (EDS) mapping analysis, TEM, and FT-IR. Starch plays a crucial role in the stabilization and dispersion of Se NPs, as noticed from the TEM and EDS investigations. Furthermore, the atomic ratio of Se distribution over the starch surface is approximately 1.67%. The current study was conducted on four groups of adult male rats, and the oral daily treatments for 28 days were as follows: group I served as control, group II received Se-NPs@starch, group III was exposed to melamine, while group IV was treated with melamine and Se-NPs@starch. The results reveal a significant alteration in the histoarchitecture of both hepatic and renal tissues induced by melamine. Furthermore, elevated liver and kidney function markers, high malondialdehyde, and increased expression levels of apoptosis-related genes besides a reduction in GSH and expression levels of antioxidant genes were observed in the melamine-exposed group. Interestingly, the administration of the Se-NPs@starch resulted in remarkable protection of rats against melamine-induced toxicity through increasing the antioxidant capacity and inhibiting oxidative damage. Collectively, this study provides affordable starch-stabilized Se-NPs with potent biological activity, making them auspicious candidates for prospective biomedical applications.

Selenium nanoparticles with various morphology for antiangiogenesis through bFGF-mediated P13K/AKT signaling pathways

Selenium nanoparticles (Se NPs) have potential antitumor activity and immune properties. However, the mechanism between its antitumor activity and nanoparticle morphology has not been evaluated. Therefore, a simple method was used to synthesize three special shapes of Se NPs, which are fusiform, flower and spherical. Compared with fusiform selenium nanoparticles (Se NPs (S)) and flower-shaped selenium nanoparticles (Se NPs (F)), spherical selenium nanoparticles (Se NPs (B)) have better cell absorption effect and stronger antitumor activity. HRTEM showed that Se NPs (B) entered the nucleus through endocytosis and inhibited tumor angiogenesis by targeting basic fibroblast growth factor (bFGF). Se NPs (B) can competitively inhibit the binding of bFGF to fibroblast growth factor receptor through direct binding to bFGF, down-regulate the expression of bFGF in human umbilical vein endothelial cells (HUVEC), and significantly reduce the MAPK/Erk and P13K/AKT pathways activation of signaling molecules to regulate HUVEC cell migration and angiogenesis. These findings indicate that Se NPs have a special role in antitumor angiogenesis. This research provides useful information for the development of new strategies for effective drug delivery nanocarriers and therapeutic systems.

Chitosan-selenium nanoparticles (Cs–Se NPs) modulate the photosynthesis parameters, antioxidant enzymes activities and essential oils in Dracocephalum moldavica L. under cadmium toxicity stress

In view of damaging impacts of cadmium (Cd) toxicity on various vital processes of plants and strategies for alleviating these effects, selenium (Se) application has been recently achieved great attention. In addition, chitosan (CS) and its nano-form, besides many positive effects on plants, could be considered as an excellent adsorption matrix and a carrier for a wide range of materials like Se with various applications in agricultural sector. For that point, the combination nano-form of Se and CS (CS–Se NPs), using CS as a carrier and control releaser for Se, could enhance Se efficiency particularly at lower doses under stress conditions. Therefore, Se (10 mg L−1), CS (0.1%) and CS-Se NPs (in two concentrations; 5 and 10 mg L−1) were applied on Moldavian balm plant under 0, 2.5 and 5 mg kg−1 Cd-stress conditions. The results demonstrated that mostly Se and CS-Se NPs treatments could lessen negative effects of Cd-stress conditions through enhancing agronomic traits, photosynthetic pigments, chlorophyll fluorescence parameters and SPAD, proline, phenols, antioxidant enzymes activities and some dominant constituents of essential oils and decreasing MDA and H2O2. These encouraging impacts were more significant at lower dose of CS-Se NPs (5 mg L−1) introducing it as the best treatment to ameliorate Moldavian balm performance under Cd-stress conditions. In conclusion, CS-Se NPs could be considered as a supportive approach in plant production mainly under different heavy metal stressful conditions and probably a potential plant growth promoting and stress protecting agent with new outlooks for applying in agricultural sector.

The Advancing of Selenium Nanoparticles Against Infectious Diseases.

Infectious diseases, caused by the direct exposure of cellular or acellular pathogens, are found to be closely associated with multiple inflammation and immune responses, keeping one of the top threats to human health. As an indispensable trace element, Selenium (Se) plays important roles in antioxidant defence and redox state regulation along with a variety of specific metabolic pathways. In recent decades, with the development of novel nanotechnology, Selenium nanoparticles (Se NPs) emerged as a promising agent for biomedical uses due to their low toxicity, degradability and high bioavailability. Taking the advantages of the strong ability to trigger apoptosis or autophagy by regulating reactive oxygen species (ROS), Se NPs have been widely used for direct anticancer treatments and pathogen killing/clearance in host cells. With excellent stability and drug encapsulation capacity, Se NPs are now serving as a kind of powerful nano-carriers for anti-cancer, anti-inflammation and anti-infection treatments. Notably, Se NPs are also found to play critical roles in immunity regulations, such as macrophage and T effector cell activation, which thus provides new possibilities to achieve novel nano-immune synergetic strategy for anti-cancer and anti-infection therapies. In this review, we summarized the progress of preparation methods for Se NPs, followed by the advances of their biological functions and mechanisms for biomedical uses, especially in the field of anti-infection treatments. Moreover, we further provide some prospects of Se NPs in anti-infectious diseases, which would be helpful for facilitating their future research progress for anti-infection therapy.

Antibacterial thin film nanocomposite forward osmosis membranes produced by in-situ reduction of selenium nanoparticles

In this study, we present a facile method for the in-situ reduction of selenium nanoparticles (Se NPs) on a thin-film composite forward osmosis (FO) membrane. As an essential nutrient, Se is superior in terms of both low off-target toxicity and application potential. Given the superiority of Se, this study explored the application of Se NPs in the field of FO membrane separation and water treatment. In this study, Se NPs were evenly distributed on the polyamide layer of thin film nanocomposite (TFN) FO membranes and were found to significantly improve the hydrophilicity of the membrane surface and reduce the zeta potential value. Moreover, the water flux increased from 14.0 L m−2 h -1 (TFC FO) to 16.6 L m−2 h -1 (1 wt% Se TFN FO), while a slight increase in the reverse salt flux was observed. The diffusion inhibition zone tests revealed distinct antibacterial effects, and the bacteriostatic rate (BR) and live and dead cell staining tests showed a high BR (100 % of 1.5 wt% Se) of the Se NP-modified membranes on both gram-negative (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). Thus, Se NPs as antibacterial agents offer a new option for membrane functionalization and water treatment.

EFFECT OF BIOSYNTHESIZED ZN AND SE NANOPARTICLES ON THE PRODUCTIVITY AND ACTIVE CONSTITUENTS OF GARLIC SUBJECTED TO SALINE STRESS

This study is to green synthesize zinc oxide and selenium nanoparticles (ZnO NPs and Se NPs)through aqueous extract of moringa leaves and confirming the synthesis by specialized equipment analysis. In addition, to study the effect of their nanoparticles on the growth, yield, active constituents, and antioxidant activity of garlic plants (Sids 40) under saline stress conditions. The size formed of ZnO NPs was 30-55 nm and Se NPs was 3.5-17 nm. These nanoparticles had a positive effect on all growth and yieldparameters, however; the maximum values were recorded when ZnO NPs applied at 2 ppm. Regarding the active constituents in garlic bulbs, the nanoparticles had an effective role in increasing total phenolic compounds and flavonoids, while Se NPs promoting these compounds, especially at 0.5 ppm. For the GC-MS analysis, it was noted that the major bioactive compounds were about 27. Moreover, nanoparticles had a high effect in increasing the phytoconstituents. As for the antioxidant activity (scavenging DPPH and H2O2), the results showed that the use of nanoparticles led to a high increase in the elimination of these free radicals. Among these, all Se NPs treatments showed the highest potential to scavenge DPPH and H2O2, compared with the control and ZnO NPs. The maximum scavenging of DPPH and H2O2were recorded by Se NPs at 2 and 1 ppm, respectively.

Comparing the Histopathological Effects of Selenium Nanoparticles and Selenium Nanocomposites in Rat Models

Background: Selenium nanoparticles (Se NPs) and selenium nanocomposites (Se NCs) have different biological effects. The current study aimed to compare the effects of newly synthesized Se NPs and Se NCs on biochemical and histopathological parameters of rats. The synthesized Se NPs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), and scanning electron microscopy (SEM) techniques. Materials and Methods: Adult male Wistar rats were divided into four equal groups to examine the biological effects of Se NPs. Control rats received saline intraperitoneally while experimental rats were received four-week intraperitoneal injections of Se powder, Se NPs, and Se NCs at the dose of (0.4 mg/kg). After four weeks, serum was obtained by the conventional methods, and then rats were sacrificed to separate liver, kidney, and testis tissues for histopathological examinations. Results: The intraperitoneal injection of Se powder caused significant elevations in serum liver enzyme levels, serum blood urea nitrogen (BUN) lipid peroxidation, and serum creatinine levels (P<0.05). The histopathological investigations showed necrosis and fatty change in liver. Kidney sections showed cytoplasmic vacuolation and hyaline casts, and the testis sections showed degeneration of seminiferous tubules. Se NPs intraperitoneal injections at a dose of 0.4 mg/kg caused no significant effects on liver enzymes, malondialdehyde (MDA) content, and histopathological changes while significantly increased serum BUN and creatinine levels (P<0.05). The group treated with Se NCs showed normal biochemical and histopathological parameters (P<0.05). Conclusion: The current study proved the toxicity of Se powder; however, nano-formulations of Se showed fewer side effects.

High selectivity and adsorption proficiency of surfactant-coated selenium nanoparticles for dye removal application.

The rate of environmental pollution augmenting at an alarming rate due to the continuous disposal of toxic dyes directly into the environment and water streams. The direct contact of dyes with water resources directly affects the living beings. The identification of superior methods for the treatment of water pollution caused due to effluent dyes needs higher consideration among researchers for the well-being of living flora and fauna. The available methods for controlling the decontamination of water through toxic dyes have various drawbacks. So, it is highly significant to develop such materials which can easily adsorb the dyes without causing any toxic effect on the environment and living beings. While keeping all the facts in mind, the current work highlights the comparative enhancement in adsorption capacity and selectivity of Brij-58-coated selenium nanoparticles (Brij-58@Se NPs) towards the removal of bromophenol blue (BB) dye from series of chosen dyes in aqueous media. The fabricated Se NPs were methodically characterized and the adsorption behaviour displayed fast adsorption efficiency (98% within 6 min) for BB dye out of series of chosen dyes. The optimization studies were carried out to verify the influence of working variables such as pH (2.0-12.0), response time (1-10 min), dosage amount (0.1-80 mg/l) and concentration of BB dye (1-70 ppm). The adsorption process found to be best fitted for Freundlich adsorption isotherm and pseudo first-order kinetic model. The interference studies of different cationic, anionic species including dyes or metal ions suggested the higher efficiency of Brij-58@Se NPs for adsorptive removal of BB dye from aqueous media. The efficacy of the adsorbent was further tested in six different water resources and displayed 95% adsorption efficiency for BB dye in different wastewater samples. Therefore, Brij-58@Se NP is expected as a potential adsorbent for the adsorption of organic dyes from wastewater samples.

Synthesis of C:Se nanoparticles via laser ablated with magnetic field on porous silicon for gas sensor applications

The presented study synthesized C:Se NPs via a combination of the laser along with magnetic field at various laser pulse energies 200, 600 and 1000mJ with 100 shots, have been deposited on the porous silicon (PS) through the use of drop-casting method. The pattern of the X-ray diffraction (XRD) had indicated the nanocrystaline of specimens. In Atomic force microscopy (AFM), which shows agglomeration of C:Se NPs increased, the distribution of the granularity showed that the distribution of part was almost Gaussian, also the transmission electron microscope (TEM) indicated that the synthesized C:Se particles have an average particle size of 35 nm. Bright-field TEM images show complementary contrast, confirming the formation of core/shell structures. The optical measurements in wavelength range ultraviolet-visible near infrared (UV–vis–NIR) as well as a transition of indirect type with 4 eV band gap is specified. Also, the electrical characteristics like barrier height (ΦB), ideal factor (n) for Al/C:Se NPs/PS/Si/Al heterojunction were concluded with measurements of current-voltage (I-V). Lastly, the operation temperature variations associated with NO2 and NH3 gas sensors are subjected to fabrication from the prepared samples on response time, sensor sensitivity and recover time was examined. The maximum sensitivity of C:Se/PS at 1000 mJ gas sensor to 60 ppm of NO2 about 202.5% at around 100 °C,also the maximum sensitivity of C:Se/PS at 1000mJgas sensor to 200 ppm of NH3 can reach 17.9%, and the optimum sensing temperature of C: Se/PS sensor is at around 150 °C.

Delineation of cellular stages and identification of key proteins for reduction and biotransformation of Se(IV) by Stenotrophomonas bentonitica BII-R7

The widespread use of selenium (Se) in technological applications (e.g., solar cells and electronic devices) has led to an accumulation of this metalloid in the environment to toxic levels. The newly described bacterial strain Stenotrophomonas bentonitica BII-R7 has been demonstrated to reduce mobile Se(IV) to Se(0)-nanoparticles (Se(0)NPs) and volatile species. Amorphous Se-nanospheres are reported to aggregate to form crystalline nanostructures and trigonal selenium. We investigated the molecular mechanisms underlying the biotransformation of Se(IV) to less toxic forms using differential shotgun proteomics analysis of S. bentonitica BII-R7 grown with or without sodium selenite for three different time-points. Results showed an increase in the abundance of several proteins involved in Se(IV) reduction and stabilization of Se(0)NPs, such as glutathione reductase, in bacteria grown with Se(IV), in addition to many proteins with transport functions, including RND (resistance-nodulation-division) systems, possibly facilitating Se uptake. Notably proteins involved in oxidative stress defense (e.g., catalase/peroxidase HPI) were also induced by Se exposure. Electron microscopy analyses confirmed the biotransformation of amorphous nanospheres to trigonal Se. Overall, our results highlight the potential of S. bentonitica in reducing the bioavailability of Se, which provides a basis both for the development of bioremediation strategies and the eco-friendly synthesis of biotechnological nanomaterials.