Search

The present work aimed to account for the first time green, and eco-friendly synthesis of Fe3O4/Cu nanocomposite as magneto-recyclable photocatalyst using Rosmarinus officinalis leaves aqueous extract. R. officinalis leaves extract played three significant roles in improving physicochemical properties of Fe3O4 nanoparticles as reducing, stabilizing and capping agents and can convert Cu2+ ions into Cu0. Several characterization techniques were employed to investigate the crystal structure, surface chemistry, morphology, and optical properties of the produced nanomaterials. The UV–Vis DRS spectra exhibited a low band-gap (1.7 eV), appropriate for an effective visible-light degradation. Effectiveness of Fe3O4 nanoparticles and Fe3O4/Cu nanocomposite as photocatalysts were examined under visible light illumination on an aqueous contaminant solution. Degradation efficiencies of methyl orange, imipenem, and imatinib mesylate, three types of organic contaminations were about 50–96% after 5400 s irradiation over Fe3O4 nanoparticles and Fe3O4/Cu nanocomposite. Total organic carbon analysis results confirmed degradation efficiencies of all samples. Trapping experiments results verified that O2− was the main oxidative species in the degradation of organic contaminations. The as-prepared photocatalysts could be reused after five successive cycles with no significant reduction in degradation efficiency. Besides, biogenic nanoparticles and nanocomposite were promoted H2O2 production. The photochemical production of H2O2 was achieved under visible light irradiation toward the two-electron oxygen reduction reaction. The plausible mechanisms for photocatalytic and degradations were proposed, which suggested the prepared photocatalysts' remarkable potential for removing contaminants with complex structures.

This work reports the synthesis and application of uniform and spherical molecularly imprinted polymeric (MIP) nanobeads for selective and efficient preconcentration of Rosmarinic acid (RA). The as-prepared RA MIP nanobeads were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) techniques. As analyzed, nano-sized particles of MIP with spherical and uniform shape and the average size of 88 nm were synthesized. The prepared MIP nanobeads were used in an ultrasonic-assisted dispersive solid phase extraction approach (UA-DSPE) for extraction of RA as a natural antioxidant specie from the extract of Salvia Officinalis leaves. In UA-DSPE process, the RA content of the samples was determined using high-performance liquid chromatography (HPLC). The highest recovery percentage (>90%) was observed after loading of RA solution (pH 5.7) and after elution with 3 mL of acetic acid aqueous solution, followed by 6 min sonication. The selectivity studies demonstrated a selective and high affinity binding of the template molecule (i.e. RA) toward MIP sorbent compared to other compounds such as gallic acid, caffeic acid, and pyrocatechol.

Summary The acquired resistance of plants to root-knot nematodes (Meloidogyne spp.) can be achieved by applying chemical inducers, such as β-aminobutyric acid (BABA). Recently, the use of metal nanoparticles with multifunctional use against plant-parasitic nematodes has been presented. In this study, silver nanoparticles (AgNPs) were synthesised using the aqueous leaf extract of Malva sylvestris. The effect of different AgNPs concentrations on hatching and mortality of the second-stage juveniles (J2) of Meloidogyne javanica was investigated in vitro. The effects of AgNPs on eggplants infected with 0, 1, 2, 4 and 8 eggs (cm3 soil)−1 were investigated under glasshouse conditions. The combined effects of AgNPs and BABA on eggplants infected with 4 and 8 eggs (cm3 soil)−1 were investigated in another study. The results showed that increasing the concentration of AgNPs the hatching of M. javanica decreased and the mortality of J2 increased. The number of eggs, galls, egg masses and reproduction factor in plants treated with AgNPs infected with 4 eggs (cm3 soil)−1 decreased by 43.4, 24.7, 23.5 and 43.2%, and in plants infected with 8 eggs (cm3 soil)−1, decreased by 64.5, 25.5, 63.1 and 64.5%, respectively, compared to control plants. The reproduction factor in infected plants with 4 and 8 eggs (cm3 soil)−1 that were treated with BABA (1 mM) and AgNPs decreased by 51.6 and 55.9%, respectively, compared to control plants. The results of this study demonstrated the effects of BABA, AgNPs and the combination of these two substances in reducing the damage of different inoculum densities of M. javanica in eggplant.

In this work, novel 2-mercaptoethanol capped zinc sulfide (ZnS) quantum dots (QDs) embedded polyethersulfone (PES) nanocomposite membranes were fabricated which revealed wh improved antifouling properties and dye separation performance. A simple water-based precipitation approach was used to obtain 2-mercaptoethanol capped ZnS QDs at ambient temperature. The resulting membranes were fully identified with SEM, AFM, ATR-FTIR analyses, and also underwent porosity and contact angle tests. The developed nanostructure membranes exhibited a remarkable fouling reduction in bovine serum albumin (BSA) protein filtration, as featured by a declined average surface roughness. The flux recovery ratio (FRR) was improved considerably from 52.6% for the neat PES to 87.9% for nanocomposite membrane by inserting 2 wt.% ZnS QDs. The contact angle of membrane decreased, while porosity size was enlarged by increase of the QDs loading. The prepared nanocomposite membranes showed an increased Reactive Red 195 rejection (from 91.3% to 96.1%) and an enhanced water and dye solution flux (from 121 to 163 L m−2 h−1) with respect to the bare PES membrane. Thus, the results proved the potential of the novel QDs/PES membrane for the dye separation applications.

In this study, we designed Fe3O4 nanoparticles and heterogeneous Fe3O4-Au nanocomposites with a mean size of 21 and 27 nm that synthesized by Foeniculum vulgare seed extract to photodegrade organic micropollutants under UV and visible light irradiation. The physiochemical characteristics of biogenic nanoparticles/nanocomposite are described by XRD, FTIR, UV-Vis, SEM, EDX, and X-ray elemental mapping. In the presence of nanoparticles and nanocomposites under UV irradiation, the total degradation of contaminants is about 85–90% after 2100 s, while under visible light irradiation, degradation efficiencies are about 70–85% after 4800-s irradiation. Total organic carbon analysis results confirmed photodegradation efficacies. Also, the scavenger’s experiments show that hydroxyl radical is the most important specie in the degradation of pollutant model. It can be concluded clearly that Fe3O4 green nanoparticles and Fe3O4-Au green nanocomposite are very simple and effective photocatalyst for degradation of organic pollutants in very short time under illumination.

In this work, a green and plant-mediated approach based on the aqueous extract of the Ficus Johannis plant was presented for synthesis of zinc sulfide (ZnS), as efficient and eco-friendly nanophotocatalysts (NPCs). In the first phase, after identification, collection, and drying of the plant, the aqueous extract of the plant fruits was prepared by microwave-assisted extraction (MAE) technique. The characterization of the as-prepared ZnS NPCs was carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution scanning electron microscopy (HR-SEM), Fourier-transform infrared spectroscopy (FT-IR), fluorescence, and UV–Vis absorption spectroscopy. The fluorescence and UV–Vis absorption investigations showed an obvious emission peak between 420 and 440 nm with a broad absorption band between 290 and 320 nm. From SEM and TEM images, the particle size of the ZnS NPCs was estimated to be smaller than 20 nm. In the next step, the application of the as-prepared ZnS NPCs was examined as for photodegradation of some industrial pollutants including naphthalene (Naph), anthracene (AnT), 4- chlorophenol (4-CP), and 4- nitrophenol (4-NP). The effect of experimental parameters on photodegradation percentage of the pollutants such as NPCs dosage, initial pollutant concentration, UV-irradiation time, scavenger type was studied. Under optimum conditions, high-degradation efficiency was obtained using a low amount of ZnS NPCs, after 120 min UV irradiation. Finally, the probable mechanism of the presented heterogeneous photodegradation approach was discussed, too.

Here, calcium tungstate nanoparticles (CWONPs) were synthesized by the hydrothermal method. The reaction parameters including calcium salt concentration, surfactant concentration, reaction time and temperature have been optimized by Taguchi Design Method for smaller particles size. The morphology, size, crystallinity and chemical structure of nanoparticles were investigated by different methods. The optimized calcium tungstate nanoparticles (opt-CWONPs) with average size of 51 nm were showed outstanding removal effectiveness for three different pollutants including methyl orange, imipenem and imatinib mesylate over UV illumination. Nearly, 100% of methyl orange, 98% of imipenem and 60% of imatinib mesylate are degraded at 1800s over opt-CWONPs with banggap 3.7 eV. In addition, a modified carbon paste electrode was formed with opt-CWONPs and linear sweep voltammetry was used to analyze its electrocatalytical activity in acidic media. The findings showed that the carbon paste electrode modified by opt-CWONPs had a higher current density in the hydrogen evolution reaction (HER) than the bare carbon paste electrode. This article has subsequently revealed a revolutionary method for opt-CWONPs preparation and demonstrated its multifunctionality as photocatalyst and electrocatalyst active ingredients.

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

In the past few decades, extensive discussions have been on the impact of artificial sweeteners on the risk of cancer. The present study aimed to evaluate the interaction of saccharin (SA) and sodium saccharin (SSA) with the promoter of the human p53 gene. The binding ability was assessed using the spectroscopic technique, molecular docking and molecular dynamics (MD) simulation methods. Free energy of binding has been calculated using Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) method. Fluorescence spectra of mentioned gene with concentration profiles of SA and SSA were obtained in a physiological condition. A gradual increase without any significant spectral shift in the fluorescence intensity of around 350 nm was evident, indicating the presence of an interaction between both compounds and gene. The docking results showed that both compounds were susceptible to bind to 5'-DG56DG57-3' nucleotide sequence of gene. Furthermore, the MD simulation demonstrated that the binding positions for SA and SSA were 5'-A1T3T4-3' and 5'-G44T45-3' sequences of gene, respectively. The binding of these sweeteners to gene made significant conformational changes to the DNA structure. Hydrogen and hydrophobic interactions are the major forces in complexes stability. Through the groove binding mode, the non-interactive DNA-binding nature of SSA and SA has been demonstrated by the results of spectrofluorometric and molecular modeling. This study could provide valuable insight into the binding mechanism of SA and its salt with p53 gene promoter as macromolecule at the molecular level in atomistic details. This work can contribute to the possibility of the potential hazard of carcinogenicity of this sweetener and to design and apply new and safer artificial sweeteners. AbbreviationsSASaccharinSSASodium SaccharinPp53gpromoter of human p53 geneMDMolecular dynamicsRMSDRoot-mean-square deviationRMSFRoot-mean-square fluctuationRgRadius of GyrationSASASolvent-Accessible Surface AreaADIAcceptable daily intakeMM/PBSAMolecular Mechanics/Poisson-Boltzmann Surface AreaCommunicated by Ramaswamy H. Sarma.

In this study, a simple, rapid, and efficient plant-mediated green approach was presented for the synthesis of stable and ultra-small zinc telluride quantum dots (ZnTe QDs) using the aqueous extract of the Ficus johannis plant. Two modern techniques, namely ultrasonic and microwave techniques, were applied to prepare the plant extracts, which were then used as stabilizing precursors in the synthesis of ZnTe QDs. The synthesized samples were characterized via different techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible absorption, photoluminescence and Fourier transform infrared spectroscopy. The TEM images confirmed the formation of ultra-small nanoparticles with an average size of 8 nm. According to the optical characterization, a wide absorption band around 390 nm and an intense emission peak at 463 nm clarified the successful synthesis of ZnTe QDs. After synthesis and characterization, the antioxidant, antimicrobial, and antifungal potentials of the as-prepared QDs as well as the plant extracts were examined by different tests, comparatively. In addition, the determination of the total phenolic and flavonoid contents of the as-prepared samples was carried out. Moreover, the toxicity of the samples was investigated by Artemia uramiana from their brine shrimp lethality potentials. In the cytotoxicity tests, the inhibition of root growth was considered as an indicator to evaluate the cytotoxicities of the samples.

In the present study, electrochemical studies and potentiometric determination of captopril (CAP) drug were presented using a glassy carbon electrode (GCE) and carbon paste electrode (CPE), respectively; which is modified with a synthetic nano-structured molecularly imprinted polymer (MIP). CAP-MIP sample with an average particle size of 95 nm was synthesized using a precipitation polymerization method. The electrochemical behavior of CAP was studied on a MIP modified GCE, in an aqueous solution at pH 3.0. The electron transfer coefficient (α) was determined for the CAP drug, using electrochemical approaches. The prepared CAP-MIP was also used as a modifier in a CPE to design a selective CAP sensor, before its potentiometric determination. The modified CPE exhibits a good electrochemical response with a Nernstian slope of 59.15 ± 1.5 mV per decade over a wide linearity in the concentration range of 3.0 × 10−9–1.0 × 10−1 mol L−1. The cyclic voltammetry results were in good agreement with the electrochemical studies for the 1H+/1e− process. The designed electrode indicates a reasonable selectivity for CAP over other studied drugs such as ibuprofen, paracetamol, acyclovir, pyrazinamide, dimenhydrinate, and naproxen as well as with an excellent applicability in some pharmaceutical products.

The present study reported a green approach for sonochemical-assisted synthesis (SAS) of cadmium selenide nanoparticles (CdSe NPs) by using the aqueous extract of Leontice Leontopetalum plant. The aqueous extract was obtained by ultrasonic- assisted extraction (UAE; 15 min, 50°C) and microwave- assisted extraction (MAE; 15 min, 180, and 270 W) as two instrumental techniques. Next, the as-prepared aqueous extracts were used in a plant-mediated synthetic approach for the synthesis of CdSe NPs by applying the SAS technique. The synthesized samples were characterized via different techniques; including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible absorption; photoluminescence, and Fourier transform infrared spectroscopy. The average particle size of the prepared CdSe NPs was estimated below 50 nm. UV-Vis absorption and fluorescence techniques indicate a wide absorption band around 360–420 nm and an intense emission peak around 460 nm, respectively. After green synthesis and characterization, antimicrobial, antioxidant, and antifungal properties of the aqueous plant extracts as well as their corresponded CdSe NPs were evaluated by different assays, comparatively. Moreover, the genotoxicity and toxicity potential of the samples were investigated. The results indicate the significant antimicrobial activity of the extracts as well as the CdSe NPs, with the negligible toxicity and genotoxicity impacts.

In this study, the effect of three different transition metal ion dopants (Mn

In this study, we designed Fe

A simple biogenic approach for synthesis of Fe

In this study, a new Cr(III)-imprinted polymer (Cr(III)-IIP) is prepared from CrCl3·6H2O, methacrylic acid functional monomer, ethyleneglycoldimethacrylate cross-linking agent, 2,2ʹ-azobisisobutyronitrile radical initiator and 2,2-(azanediylbis (ethane-2,1-diyl))bis(isoindoline-1,3-dione) ligand. To obtain the maximum adsorption capacity, the optimum condition was studied through pH, type and concentration of eluent, IIP weight, sample volume as well as the adsorption and desorption times. The Cr(III) ion content was determined via flame atomic absorption spectrometer. In optimum conditions, the adsorption capacity of the IIP for Cr(III) was obtained to be 74.65 mg g−1, using 50 mg of IIP and the initial pH solution of 3.0. Both the adsorption and desorption times for quantitative analyses of Cr(III) ions were 15 and 5 min; respectively. After elution of the adsorbed ions by 3 mL of 4 mol L−1 HNO3 aqueous solution, the established IIP-based SPE procedure provides a reasonable pre-concentration factor of 100. The IIP-based pre-concentration method provides a low detection limit of 1.7 µg L−1 with good repeatability (RSD = 3.22%). Reusability studies confirmed that synthesis IIP is reusable and recoverable up to six cycles. According to the selectivity experiments, it was concluded that the prepared sorbent possesses more affinity toward Cr(III) ions than other ions such as Al3+, Pb2+, Cu2+, Mn2+, Fe2+, Zn2+, and Ni2+ ions. To evaluate the potential applicability of the proposed separation method, the pre-concentration and determination of trace amounts of Cr(III) were performed successfully in food samples with complex matrices, a bestial sample (i.e. cow liver) and an herbal product (i.e., broccoli) as real samples.

Herein, novel nitrogen-doped nanoporous carbons possessing 2.63 at.% N and high porosity were prepared using nitrogen-rich carbon quantum dots (N-CQDs) via a facile chemical activation. To this end, after performing the hydrothermal process on the raw materials, chemical activation was carried out by various KOH/N-CQDs ratios (2:1 to –4:1), resulting in unique micro-mesoporous structures (i.e., HNAC samples). In this approach, a large surface area (1477 m2g−1) and pore volume (1.05 cm3g−1) were obtained, where the micropore volume was increased by decreasing the KOH/N-CQDs ratio, activation time and augmenting the activation temperature, that caused considerable adsorption at 1 bar. It is worth mentioning that mesopores could be generated by condition optimization that led to higher adsorption at high pressure. Due to their large surface area and high nitrogen loading, the HNAC samples demonstrated excellent H2S and CO2 adsorption capacity at ambient conditions (9.28 mmolg−1 for H2S and 4.28 mmolg−1 for CO2 at 1 bar and 25 °C) and at higher pressures (18.0 mmolg−1 for H2S and 6.20 mmolg−1 for CO2 at 10 bar and 25 °C). According to the significant performance of the prepared nanosorbents along with stable cyclic adsorption-desorption performance, the HNACs are proposed as promising adsorbents with outstanding adsorption.

The present study reported a green approach for sonochemical-assisted synthesis (SAS) of cadmium selenide nanoparticles (CdSe NPs) by using the aqueous extract of Leontice leontopetalum plant. The aqueous extract was obtained by ultrasonic- assisted extraction (UAE; 15 min, 50 °C) and microwave- assisted extraction (MAE; 15 min, 180, and 270 W) as two instrumental techniques. Next, the as-prepared aqueous extracts were used in a plant-mediated synthetic approach for the synthesis of CdSe NPs by applying the SAS technique. The synthesized samples were characterized via different techniques; including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible absorption; photoluminescence, and Fourier transform infrared spectroscopy. The average particle size of the prepared CdSe NPs was estimated below 50 nm. UV–Vis absorption and fluorescence techniques indicate a wide absorption band around 360–420 nm and an intense emission peak around 460 nm, respectively. After green synthesis and characterization, antimicrobial, antioxidant, and antifungal properties of the aqueous plant extracts as well as their corresponded CdSe NPs were evaluated by different assays, comparatively. Moreover, the genotoxicity and toxicity potential of the samples were investigated. The results indicate the significant antimicrobial activity of the extracts as well as the CdSe NPs, with the negligible toxicity and genotoxicity impacts.

In the present study, microwave assisted extraction (MAE) was applied as an efficient, green and rapid approach to prepare the aqueous extract of Suaeda aegyptiaca (SA) plant. The obtained aqueous extracts at two different irradiation power (90 and 270W; 15min) in MAE process as well as maceration method (24h) were used in a green and eco-friendly approach for the synthesis of zinc oxide nanoparticles (ZnO NPs). The synthesized ZnO NPs have been characterized via different techniques including UV-Vis absorption; fluorescence and Fourier transform infrared (FT-IR) spectroscopices, scanning electron microscopy (SEM), and X-ray diffraction (XRD). According to the results, the average size of the prepared ZnO particles was estimated around 60nm. A broad absorption band around 382nm in UV-Vis absorption spectrum and a maximum emission at wavelength of 458nm in fluorescence spectrum clarified the successful biosynthesis of ZnO NPs. Moreover, the biological properties of the extracts and biosynthesized ZnO NPs were investigated by antimicrobial tests (i.e. Well-diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) tests), antifungal and antioxidant tests (total phenolic and flovonoid content, antioxidant activity against dipheny-picrylhydrazyl (DPPH), and ethylbenzothiazolin-6sulphonic acid (ABTS+)). Finally, DNA cleavage potential of the samples was studied, too.

In this study, a new carbon paste electrode (CPE) modified with porphyrin-based ion imprinted polymer (IIP) was designed and applied for the potentiometric determination of Cu2+ ions in aqueous solutions. The Cu-IIP was prepared using methacrylic acid, ethyleneglycoldimethacrylate monomers, in the presence of a copper complex of 5,10,15,20-tetrakis(4-hydroxyphenyl)-porphyrin. After polymerization, the prepared polymer was eluted by an aqueous solution of hydrochloric acid to leach the imprinted ions, which results in an obvious change in its color from purple to light brown. By microscopic analysis, the mean particle size of the prepared leached IIP was estimated to be around 60 nm. After characterization, the prepared IIP NPs were used as a modifier to design a modified CPE for potentiometric determination of Cu2+ ions in aqueous solutions. As found, at the optimum paste composition, the modified potentiometric sensor exhibited an excellent Nernstian response (30.15 ± 0.2 mV dec−1) to the logarithm of Cu2+ ion concentration over the concentration range of 4.0 × 10−9 to 2.0 × 10−1 mol L−1. Moreover, the designed sensor showed a low detection limit (2.0 × 10−9 mol L−1) with a short response time (∼5 s) and acceptable stability (at least 2 months). In addition, the sensor was successfully applied as a reasonable indicator electrode in potentiometric titration (against EDTA) with high precision and accuracy. Applicability of the IIP NP modified CPE was examined and confirmed by analysis of various water samples for the determination of Cu2+ ions.

In this study, a comparison study between two recent extraction methods, namely ultrasound-assisted molecularly imprinted polymeric nanoparticles solid-phase extraction (US-MIPNPs-SPE) and the solidification of floating organic drop-assisted dispersive liquid–liquid microextraction (SFOD-DLLME), for the preconcentration and separation of morin is presented. The morin-MIP NPs, with an average particle size of 57 nm, were synthesized using a precipitation polymerization strategy using methacrylic acid (MAA) and ethyleneglycoldimethacrylate (EGDMA) as functional and cross-linking monomers, respectively. After the synthesis and characterization, the prepared MIP was used as an efficient nano-scale sorbent in the ultrasound-SPE procedure. The effects of various parameters on the extraction efficiency of the morin, including the pH of the sample solution, adsorption and desorption times, initial sample volume, and volume and type of eluent, were investigated in batch experiments. After optimization, isotherm and kinetic models for the adsorption of morin onto morin-MIP NPs were evaluated and fitted. In the SFOD-DLLME procedure, the affecting parameters on morin recovery, such as the type, the volume of extraction and dispersive solvents, pH of the initial sample solution, extraction time, and ionic strength, were studied too.

Here, a new flow injection analysis-solid phase extraction (FIA-SPE) technique was developed by using zinc ion imprinted polymeric nanoparticles (Zn-IIP NPs) for the separation and preconcentration of Zn2+ ions from aqueous solutions. For the synthesis of a nano-sized Zn-IIP, a stable chelate of Zn2+ ions with 3,5,7,2′,4′-pentahydroxyflavone was formed and then it was copolymerized with methacrylic acid, in the presence of ethyleneglycoldimethacrylate, through a precipitation polymerization technique. From the scanning electron microscopic images, the prepared Zn-IIP NPs were observed to be spherical in shape with an average particle size of 63 nm. Based on the Brunauer–Emmett–Teller adsorption isotherm studies, the surface area, pore volume and average pore diameter of the Zn-IIP NPs were found to be 211.9 m2 g−1, 10 484 cm3 g−1 and 19.8 nm, respectively. After characterization, a FIA-SPE setup was designed based on the prepared Zn-IIP NPs, as a potential selective solid phase extractor toward Zn2+ ions. In the determination step, a standard spectrophotometric method was performed based on the formation of a colored complex between the eluted Zn2+ ions and an ethanolic solution of dithizone (λmax = 538 nm). The optimum experimental conditions for quantitative preconcentration and determination of Zn2+ ions were achieved at pH 6.0 and 5.0 of the initial sample and complex solution, at the loading and leaching flow rates of 0.5 and 5 mL min−1, respectively. The present FIA-SPE procedure offers a reasonable detection limit (3.93 × 10−7 mol L−1) and preconcentration factor (116.7) with acceptable repeatability (1.91%).

This study presents a rapid water-based chemical precipitation method for synthesis of zinc sulfide (ZnS) quantum dots (QDs), under the ultrasonic radiation, using two capping agents; including 2-mercaptoethanol and l-cysteine. It is demonstrated that by applying ultrasonic radiation, the synthesis time can be significantly decreased. The effect of capping agent type on the color specifications (using colorimetry), absorption spectra (using ultraviolet–visible absorption spectroscopy) and ZnS structure (using X-ray diffraction) are investigated. The results of the research indicate that the as-synthesized QDs were cubic structures with dimensions less than 10 nm. After characterization, the QDs samples were performed as nano-scaled photoatalysts, through a UV-driven photodegradation process for the degradation of crystalline violet (CV) as a pollutant dye. Moreover, the present study assesses the effect of operating conditions including the pH of the dye solution, UV-irradiation time, ionic strength, type and dosage of nanophotocatalyst on degradation efficiency. Experimental results of the research demonstrate the QDs can be reused for at-least five times, without a significant decrease in their photocatalytic properties. The maximum photodegradation efficiency for the CV solution adjusted at pH 11, in the presence of a low amount of QDs (i.e. 5 mg) was observed after 90 min irradiation time. Finally, the probable mechanism and kinetics of degradation reaction are proposed in the study. From the kinetic data, the acceptable regression coefficient values (>0.98) for the pseudo first-order kinetic model was obtained for expression the present QD-based photodegradation approach.

Environmental pollution has become one of the greatest problems worldwide, and photocatalysts have attracted a great deal of attention as one solution to this problem. In the present study, we report a novel environmentally friendly property of graphene quantum dots (GQDs) as efficient nano-materials for the degradation of organic pollutant dyes based on the photocatalytic behavior of GQDs under visible-light irradiation. GQD samples were derived from citric acid by a pyrolysis procedure. The synthesized GQDs were characterized by various techniques including transmission electron microscopy, UV–Vis absorption, Raman spectroscopy, fluorescence spectroscopy, and zeta potential measurements. The photocatalytic degradation of Celestine Blue (CB) was studied using GQDs under visible light irradiation. The effect of pH value, contacting time, dosage of GQDs, and initial dye concentration on the degradation kinetics of CB was systematically investigated. MS analyses were conducted to determine the degradation products evolving during the photocatalytic degradation. The possible mechanisms of degradation of CB based on GQDs under visible light are discussed as well.

In this research, the efficiencies of two methods, including quantum dots (QDs) based photocatalysis and magnetic nanoparticles (MNPs) based adsorption for the decolorization of Victoria blue R (VBR) were investigated and compared, experimentally. Synthesis of functionalized zinc sulfide (ZnS) QDs and iron oxide (Fe3O4) MNPs was carried out by a simple chemical precipitation method. 2-mercaptoethanol (ME) and sodium dodecyl sulfate (SDS) were applied for capping and surface modification of ZnS QDs and Fe3O4 MNPs, respectively. The prepared nanoparticles have been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM). The mean particle size of ZnS QDs and Fe3O4 MNPs were approximated to be 1–3 nm and 50–80 nm, respectively. In the photocatalytic and adsorption investigations, influence of affecting parameters on the removal efficiencies was studied and optimized. According to the results, both methods can be considered as green, simple and efficient strategies for the removal of organic dyes. However, comparative investigation of the characteristics of the methods demonstrated that the efficiency of the QDs based photodegradation method for the removal of VBR is higher than MNPs based adsorption process. It was also found that the maximum decolorization of 95% and 65% can be achieved after 20 and 45 min at optimum pH 10, 7.5, in the presence of 8 and 10 mg of QDs and MNPs for 30 mg/L of VBR, respectively. Finally, isotherm adsorption model and photodegradation mechanism were discussed, too.

In this work, a new modified carbon paste electrode (CPE) was constructed for potentiometric determination of naproxen (NAP) based on its imprinted polymer as a chemical modifier. An efficient precipitation polymerization method was applied for the synthesis of nano-sized NAP molecular imprinted polymer (MIP). In the preparation of MIP, methacrylic acid and ethylene glycol dimethacrylate were used as the functional monomer and cross-linking agent, respectively. The nano-sized NAP-MIP was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). SEM images confirmed the nanostructure morphology of the prepared MIP, with a particle size range of 50–80 nm. The MIP based sensor with the optimum composition exhibits a good linear response with a slope of −59.5 ± 1.5 mV per decade over the concentration range of 1.0 × 10−9.5–1.0 × 10−1 mol L−1. It has a very low limit of detection, 3.0 × 10−10 mol L−1, with a response time of 3 s. The potentiometric response of the sensor was independent of the pH of test solution in a wide range of 5.0–11.0. The proposed electrode shows a very good selectivity for NAP over other drugs. The chemically modified CPE indicated an excellent applicability for the determination of NAP in NAP capsules.

In this work, a simple, efficient and powerful photocatalytic methodology based on application of pure zinc sulfide (ZnS) quantum dots (QDs) is presented for the removal of naphthalene, as a model molecule of industrial pollutants. A facile room-temperature precipitation method was applied for the synthesis of ZnS QDs, in the presence of 2-mercaptoethanol as capping agents. The characterization of the prepared QDs was carried out by X-ray diffraction (XRD), transmission electron microscopy, high-resolution scanning electron microscopy, scanning tunneling microscopy, fluorescence, and UV–Vis absorption spectroscopies. The XRD investigations indicated that the prepared ZnS QDs are crystalline, with cubic zinc blend structure, with the average particle diameters of 1.2 nm. The fluorescence and UV–Vis absorption investigations showed a narrow and sharp emission band at 424 nm with a broad adsorption band around 235 nm. In addition, the prepared ZnS QDs were used as nanophotocatalysts, for the removal of naphthalene, as a model molecule. The influence of the experimental parameters on the removal efficiency of the ZnS QDs was studied. According to the results, the highest photocatalytic degradation of naphthalene in the presence of ZnS QDs (>95 %) was obtained at alkaline pH, in the presence of 10 mg of QDs, after a reasonable reaction time.

Here, the researchers report on the synthesis of ion imprinted polymeric (IIP) nanoparticles using a thermal polymerization strategy, and their usage for the separation of Ni(2+) ion from water samples. The prepared Ni-IIP was characterized by colorimetry, FT-IR spectroscopy, and scanning electron microscopy. It was found that the particle size of the prepared particle to be 50-70 nm in diameter with the highly selective binding capability for Ni(2+) ion, with reasonable adsorption and desorption process. After preconcentration, bound ions can be eluted with an aqueous solution of hydrochloric acid, after their complexation with dimethylglyoxime, these ions can be quantified by UV-Vis absorption spectrophotometry. The effect of various parameters on the extraction efficiency including pH of sample solution, adsorption and leaching times, initial sample volume, concentration and volume of eluent were investigated. In selectivity study, it was found that imprinting causes increased affinity of the prepared IIP toward Ni(2+) ion over other ions such as Na(+), K(+), Ag(+), Co(2+), Cu(2+), Cd(2+), Hg(2+), Pb(2+), Zn(2+), Mn(2+), Mg(2+), Cr(3+), and Fe(3+). The prepared IIP can be used and regenerated for at least eight times without any significant decrease in binding affinities. The prepared IIP is considered to be promising and selective sorbent for solid-phase extraction and preconcentration of Ni(2+) ion from different water samples.

In this work, a modified carbon paste electrode (CPE) was designed and fabricated base on magnetic functionalized molecularly imprinted polymer (MMIP) nanostructure for selective determination of Rosmarinic acid (RA) in some plant extracts. The MMIP nanostructure functionalized with –NH2 group (Fe3O4@SiO2@NH2) was prepared by surface imprinting approach and then used as modifier for destruction of modified sensor. According to sample characterization, nano-sized functionalized MMIP particles (i.e. Fe3O4@SiO2@NH2) with super-paramagnetic behavior was confirmed. The magnetization saturation value of Fe3O4@SiO2@NH2 sample was decreased from 43 emug−1 to 9 emug−1 after MIP coating. In addition, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used for study the electrochemical behavior and determination of RA on the modified CPE. Based on the results, the modified sensor has good sensitivity and selectivity for the detection of RA in the presence of other species compared to unmodified electrodes. Under optimum conditions, two linear concentration ranges (0.1−100 μM and 100−500 μM) with a low detection limit (0.085 μM), and a good precision were obtained. Finally, applicability of the designed sensor was examined for determination of RA in four plant extracts including Salvia officinalis, Zataria multiflora, Mentha longifolia, and Rosmarinus officinalis, successfully.

A simple biogenic approach for synthesis of Fe3O4/Au nanocomposite with 31 nm size using aqueous extract of Carum carvi L. seeds has been reported. Phytochemicals of Carum carvi L. seeds extract play three roles, including reducing, capping, and stabilizing agents during the nanocomposite fabrication process. Resulting nanocomposite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, differential reflectance spectroscopy, vibrating-sample magnetometer, energy-dispersive X-ray spectroscopy and X-ray elemental mapping. Differential reflectance spectroscopy investigated optical property and absorption spectra display a sharp absorption agreeing to a bandgap of 1.6 eV. Photocatalytic activity of biogenic Fe3O4/Au nanocomposite has been investigated for degradation of imatinib and imipenem drugs under UV and visible light irradiation, due to pharmaceuticals have shown to be recalcitrant in wastewater and conventional wastewater treatments do not remove them, often. Degradation efficiency of imatinib, and imipenem are about 92% and 96% after 1200 s exposure UV light and about 82% and 84% after 3600s exposure visible light in the concentration of 10 ppm drugs. Also, antimicrobial activity of biogenic Fe3O4/Au nanocomposite was investigated on three human pathogens and best result can see in 25 mg/mL of nanocomposite versuse Bacillus subtilis that inhibition zone is about 27 mm. Design of nanocomposites capable of simultaneously removing pharmaceutical and microbial contaminations is important in environments such as hospitals wastewater treatment.

In the present research, two magnetic nanophotocatalysts (MNPCs) including iron oxide nanoparticles decorated with zinc sulfide quantum dots (Fe3O4@ZnS QDs), and N,S- doped graphene QDs (Fe3O4 @ N, S-GQDs) were synthesized by the sonochemical and hydrothermal methods, respectively. The prepared MNPCs were characterized by various techniques including X-Ray Diffraction (XRD), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), UV–vis absorption and Fourier transform infrared (FT-IR) spectroscopy. The SEM images show the formation of nano- sized particles of Fe3O4, also the morphology and size of the particles were changed after their decoration with ZnS and GQDs. The magnetic saturation values of Fe3O4@ZnS QDs and Fe3O4 @ N, S-GQDs samples were obtained as 19.43 and 55.58 emu.g−1, respectively. The desirable paramagnetic properties of the samples provide suitable magnetic separation process and simple recyclyig of MNPCs. The photocatalytic activity of the as-synthesized samples was evaluated through investigating their ability to degrade an organic pollutant (i.e. Victoria Blue R dye) in aqueous media. The photodegradation efficiency was evaluated based on the decrease of VBR concentration at its maximum absorption wavelength, in the presence of Fe3O4@ZnS QDs and Fe3O4 @ N, S-GQDs as nanophotocatalyst and under ultraviolet (UV) and visible (Vis) light irradiations, respectively. In optimization experiments, the effect of various factors including pH, dye concentration, irradiation time, MNPC dosage, type and concentration of salts were investigated. The maximum photodegradation percentage of Fe3O4@ZnS QDs was obtained as 93.44 % at pH 8, and in the case of Fe3O4 @ N, S-GQDs as 96.68 % at pH 9, after 120 min irradiation.

The presence of sarcosine (SAR) in the human urine was recently suggested as a promising biomarker for prostate cancer (PCa) diagnostics. In this work, we have developed the electrochemical methods for selective determination of sarcosine (SAR) in urine samples, based on the modification of the carbon paste electrode (CPE) using uniform nano-scaled molecularly imprinted polymer (MIP). The uniform MIP nanobeads were prepared by a simple sol-gel method, using methacrylic acid as a functional monomer in a mixture of acetonitrile/water, as porogen. The usual problems related to the imprinting of the biologically polar compounds, especially; amino acids were solved by performance the present approach. After characterization, the as-synthesized MIP particles were used as chemical modifier for the construction of a modified CPE. The electrochemical behaviors and quantitative analysis of SAR were evaluated on MIP@CPE by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The modified sensor exhibits reproducible voltammetric responses with a relative standard deviation of 2.1 % and a highly selective affinity toward SAR in the presence of other co-existing and/or possible interferes. Under the optimized conditions, the peak current was found to be proportional to SAR concentration over a range of 5.0 μM–1.1 mM, with an excellent correlation coefficient (R2) of 0.9998 and an acceptable limit of detection (LOD; 0.38 μM). The practical application of the designed sensor for PCa diagnosis was evaluated by its possible applicability for the determination of SAR in urine samples of the healthy human as well as the cancer patients.

Here, a selective nano-sized magnetic sorbent based on iron oxide (Fe3O4) core and molecular imprinted polymer (MIP) shell was synthesized and used as a selective sorbent for separation of piroxicam (PIX) from aqueous media. The magnetic MIP functionalized with NH2 group (Fe3O4@SiO2@NH2) was prepared by a surface imprinting approach. The characterization of the MMIP sorbent was carried out by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Brumauer-Emmett-Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses. The results indicated that the magnetic sorbent were as microspherical nanoparticles with the average size of 50 nm, with well water-dispersibility and easily magnetically separation. The influence of the variables on PIX recovery including initial pH of sample solution, volume and concentration of the eluent, ultrasonic time, ionic strength, and the amount of MMIP were studied and optimized. The linear range (LR), relative standard deviation (RSD) and limit of detection (LOD = 3Sb/m) for determination of PIX were found to be 0.01–10.0 mg L−1, 2.56 % and 5.0 ng mL−1, respectively. The used Fe3O4@SiO2@NH2-MMIP sorbent can be regenerated with 2 ml of pure methanol, without any significant decrease in its adsorption affinity. The results demonstrated an enhanced affinity for the as-prepared MMIP toward the PIX compared to non-imprinted polymer.

Herein, we describe an electrochemical, economically viable, rapid, and optimized procedure to synthesize of sphere Al2W3O12 nanoparticles of 40 nm mean particle size. By using various techniques, size, morphology, chemical structure, and crystallinity were depicted. Considerably, the Al2W3O12 nanoparticles under UV light showed admirable elimination effectiveness for the reduction of three impurities included methyl orange as dye, imatinib mesylate as an anticancer drug with endocrine and mutagenic disruptive effects and imipenem as an antibiotic drug, and the probable mechanism is also suggested. Nearly 90% of methyl orange, 56% of imatinib mesylate, and 75% of imipenem are eradicated in 5000 s, the 1500s, and 1200s on the synthesized nanoparticles. Additionally, the nanoparticles displayed antimicrobial action versus Bacillus, Escherichia coli, and Staphylococcus aureus in the presence of 6.25, 12.5, and 25 mg/ml concentration of nanoparticles. On the other hand, the carbon paste electrode modified with Al2W3O12 nanoparticles was prepared, and its electrocatalytic activity was investigated in an acidic medium for hydrogen evolution reaction by linear sweep voltammetry method. The modified carbon paste electrode has a higher current density and lowers negative potential in the hydrogen evolution reaction compared to the unmodified electrode; the results of linear sweep voltammetry showed. Hence, this article has revealed an innovatory way for preparation Al2W3O12 nanoparticles and represented their multifunctional ability as the photocatalyst, antimicrobial agent and electrocatalytic activity.