Metal Ions Zn Research Articles

Removal of heavy metal ion by floatable hydrogel and reusability of its waste material in photocatalytic degradation of organic dyes

In the present study, a floatable carboxymethyl cellulose/polyacrylamide (PAM/CMC/DDM) hydrogel was designed by combining of mechanical frothing and in-situ polymerization method with gas bubbles template. The floating hydrogel could not only efficiently capture the heavy metal ions (Zn2+), but also be easily separated from the polluted water. After adsorption, to avoid the produced hydrogel waste, the Zn2+-impregnated hydrogels were further processed, obtaining the floatable PAM/CMC/DDM-ZnO composites, which were re-developed as photocatalyst, achieving the goal of the turning waste into treasure. Benefiting from the superior adsorption capacity and the dye-sensitized mechanism, the ZnO-loaded composite could efficiently degrade the organic dyes under visible light.

Membrane Disruption Potential of Doped Cuprous Oxide Nanoparticles Against blaNDM-1 and mcr-1 Positive Colistin Resistant E. coli

Bacterial resistance against the last-resort antibiotic “colistin” is a growing problem worldwide. Novel strategies in the field of nanotechnology for the development of suitable antibacterial drug with minimal toxicities are need of the time. Here we synthesized, Cu2O nanoparticles (Cu2O-NPs) doped with 5% Zn metal ions by adopting solution-phase method using hydrazine reduction in aqueous medium. Antibacterial assays showed a promising activity against colistin-resistant Escherichia coli isolates. Leakage assay, propidium iodide uptake assay, EtBr uptake assay, and LIVE/DEAD® BacLight™ assay showed membrane damaging activity of Cu2O-NPs. Imaging by scanning electron microscopy of NP-treated bacterial cells confirmed membrane damaging potential of used Cu2O-NPs. Toxicity assessment by cell viability assay showed no cytotoxic activity to the HEK cell line. In conclusion, our results suggest that Cu2O-NPs doped with 5% Zn may exert their antimicrobial action by disruption of the bacterial cell membrane and probably generating reactive oxygen species (ROS). We suggest that Cu2O-NPs doped with 5% Zn can be used as effective antibacterial agent.

Mixed Ternary Complexes of Sparfloxacin with Some Biologically Important Amino Acids

Potentiometric measurements for the interaction of sparfloxacin (SPFX) and the metal ions Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with the amino acids (AA) aspartic acid, alanine, valine, glutamic acid, threonine, methionine, arginine, phenylalanine were studied. The formation constants for the 1:1 binary and 1:1:1 ternary complexes in 10% (v/v) ethanol–water, I = 0.1 mol⋅L−1 KNO3 and 25 °C were measured. The values were refined using the HYPERQUAD computer program. The binding constants of M(II)–SPFX binary complexes with bovine serum albumin using absorption titration experiments were also determined.

Quantification of Ca, K, Mg, Zn and Fe elements in grape leaves from different regions of Iraq by atomic absorption spectroscopy

Grapes grow in various regions of Iraq, regions have been selected Baqubah, Al Khalesah, Nasiriyah and Sulaymaniyah, to determine the Ca, K, Mg, Zn, and Fe concentrations in their leaves for its nutritional importance using atomic absorption spectroscopy (A.A.S.). Two procedures were used for sample preparation (one of their new) and their accuracy data was evaluated, no significant differences at 97% level of confidence were found by comparison the dataset results for two methods. It has been found that Ca, K, Mg, Zn and Fe metal ion concentration are in the range of (806.9 – 2815.2), (7092.2 – 11058.7), (3708.7 – 5434.8), (17.2 – 30.8) and (114.8 – 3083) μg.g-1, respectively and follow the order K>>Mg>Ca>>Fe>Zn. However, the metal contents in vine leaves from Al Khalesah and Baqubah were relatively high in comparing to those of Sulaymaniyah and Nasiriyah. Fe metal content significantly differs from region to region and the highest concentration was found in grape leaves from Baqubah region (2890.9 – 3083.0 μg.g–1), Nasiriyah (2314.8 - 2331.3 μg.g–1), Al Khalesah (205.7 – 237.2 μg.g–1), while the lowest from Sulaymaniyah (110.9 – 114.8 μg.g-1). Thus, through the variation in the concentration of trophic metals in grape leaves from one region to another and their lack of similarity, irregularity, and incongruence, it can be concluded that the different concentration of elements depends on the quality of the soil, the irrigation water, and the climate and atmosphere (The nature of environment).

Effective removal of nickel(II) and zinc(II) in mono-compound and binary systems from aqueous solutions by application of alginate-based materials

ABSTRACT In the present study, beads of alginate, alginate-biuret and alginate-urea, were synthesised for the removal of Ni(II) and Zn(II) metal ions from aqueous solution (in single and in the bimetallic component solution). The properties of the synthesised sorbents were investigated by pHpcz, ESEM-EDX and ESEM. The modelling of experimental data demonstrate that the PSORE equation fits well the kinetic profiles, while Langmuir and also Sips models correspond well to the results of sorption isotherms (heterogeneous surface). Also, the spontaneous of process and endothermic nature of sorption was demonstrated by thermodynamic study. The maximum sorption capacity of 3.22, 4.73 and 8.53 mmol g−1 was found for the beads of alginate, alginate-biuret and alginate-urea, respectively, in case of Ni(II) while it was 6.77, 6.97 and 7.14 mmol g−1 for alginate, alginate-biuret and alginate-urea, respectively, in case of Zn(II). It was found that at 0.3 mmol L−1 concentration, Zn(II) was selectively adsorbed while Ni(II) ions were concentrated/enriched in the solution in the case of alginate-urea, but alginate-biuret and alginate beads adsorbed almost the same amount of Ni(II) and Zn(II). In the bimetallic solution, the study of selectivity coefficients (KS) shows that the alginate-urea is a selective sorbent for Zn(II) and alginate-biuret for Ni(II) ions. Therefore, the two functionalised polysaccharides do not show the same harmony in front of the two-chemical species, thus, giving the possibility of their use as selective adsorbents in solutions containing these elements and can be used in applications of different interest.

A molecular docking and dynamic approach to screen inhibitors against ZnuA1 of Candidatus Liberibacter asiaticus

ABSTRACT Huanglongbing is the most destructive disease of citrus worldwide caused by Candidatus Liberibacter asiaticus (CLas). Present control and management could not remove the huanglongbing disease. ZnuA1 is the periplasmic component of ZnuABC transporter system, involved in Zn metal ion uptake in CLas. The current study focuses on targeting the CLas ZnuA1 for the identification of potent molecules. Therefore, structure-based virtual screening was done against CLas ZnuA1, and the binding energies were evaluated using molecular docking. Potential lead molecules were selected based on binding potentials, interactions with active site residues of proteins, and pharmacophore properties. Molecular dynamics simulation and MMPBSA result confirmed that identified molecules (ZINC15670529, ZINC92774705, ZINC06510089, ZINC79841324, and ZINC69594834) bound at the active site of CLas ZnuA1 and result in the formation of highly stable CLas ZnuA1-inhibitor(s) complex as compared to CLas ZnuA1-RDS51. The study reported that identified molecules appeared to be the suitable novel putative inhibitors of CLas ZnuA1 and can be useful for further design of new derivatives with higher potency and specificity.

Pyrene Carboxylate Ligand Based Coordination Polymers for Microwave-Assisted Solvent-Free Cyanosilylation of Aldehydes.

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.

Impact of Zn2+ introduced into the central cavity of meso-tetra(4-pyridyl)porphine on its spectroscopic features

Abstract The effect of metal ion (Zn2+) introduced into the center cavity of macrocyclic meso-tetra(4-pyridyl)porphine, H2TPyP, on its spectroscopic feature is explored. Thin films of H2TPyP and ZnTPyP are successfully prepared using the thermal evaporation technique. The linear and nonlinear spectroscopic characterizations of H2TPyP and ZnTPyP films are investigated as comparative study. Our results indicate that some perturbations in the absorption spectroscopy of the H2TPyP due to Zn complexation to form ZnTPyP led to reduce four quasi degenerated Q-bands to two Q-bands and in addition to the Soret (B) band splits into two sub-bands (Bx & By) called Davydov splitting. The indirect allowed transition dominated the electronic absorption bands for both H2TPyP and ZnTPyP films and the values of optical band gap enhanced due to metalation of H2TPyP into ZnTPyP. A single oscillator model is applied to normal dispersion behavior of refractive index spectrum for H2TPyP and ZnTPyP films and from which, the dispersion parameters are calculated and exhibited an increased in their values due to insertion of Zn atom into H2TPyP. The nonlinear optical parameters such as third order susceptibility (χ(3)), nonlinear refractive index (n2) and nonlinear absorption coefficient (βc) are derived from dispersion parameters and showed a decrease in their values for ZnTPyP films with respect to H2TPyP films due to the introduction of Zn atom in central cavity of porphyrin macrocycle.

Synthesis, Characterization and Biological Activity of Transition Metals Schiff Base Complexes Derived from 4,6-Diacetylresorcinol and 1,8-Naphthalenediamine

The tridentate Schiff base ligand was prepared via condensation of 4,6-diacetylresorcinol and 1,8-naphthalenediamine in 1:1 molar ratio using conventional method. Additionally, a new series of transition metal complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) metal ions were prepared and fully characterized by elemental analysis, FT-IR, 1H NMR, UV–vis, conductivity and magnetic susceptibility measurements and theoretically through density function theory (DFT). Spectral studies suggested that, the Schiff base coordinated to the metal ions through the azomethine N, N-amine and phenolic oxygen atoms. From the elemental, magnetic susceptibility and spectroscopic data, the complexes were suggested to have octahedral geometry. The Schiff base and its metal complexes were screened for their in vitro antimicrobial activities and showed that Cd(II), Cu(II) and Cr(III) complexes have high activity against Escherichia coli, while Ni(II) and Cd(II) complexes have the highest activity against Bacillus Subtilis, Co(II) complex has the highest activity against Staphylococcus aureus and Cd(II) complex has the highest activity against Pseudomonas aeruginosa. In addition, the molecular docking study was performed to explore the possible ways for binding to crystal structure of Staphylococcus aureus nucleoside diphosphate kinase complexed with ADP (PDB ID: 3Q8U).

Using a Modified Polyamidoamine Fluorescent Dendrimer for Capturing Environment Polluting Metal Ions Zn2+, Cd2+, and Hg2+: Synthesis and Characterizations

One of the most pressing global concerns is how to provide a clean environment for future generations given the exacerbation of urban, agricultural, industrial, and economic activities due to the escalating size of the global population. A polyamidoamine (PAMAM) dendrimer peripherally modified with 4-N,N′-dimethylethylenediamine-1,8-naphthalmide as a chromophore was synthesized and utilized to capture hazardous heavy metal ions. This modified fluorescent dendrimer (FCD) was complexed with Group 12 metal ions (Zn2+, Cd2+, and Hg2+) at a 2:1 (metal: FCD) ratio. Electronic absorption, fluorescence emission, Infra-red (IR), and nuclear magnetic resonance (1H NMR) spectroscopies, conductivity, CHN elemental, thermogravimetry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses were used to characterize the resulting metal complexes. These assays revealed that the synthesized complexes were yellow-colored, thermally stable, nanoscale-sized, and composed of [M2FCD]·4Cl2. Considerable spectral shifts were observed in the emission and absorption spectra of the FCD molecule after binding the Zn2+ ions, which can be used to differentiate the Zn2+ complex from the other two complexes. This work provides basic data to facilitate the detection, quantification, and removal of environmentally hazardous heavy metal ions through complexation with a fluorescent dendrimer.

Morphology-Controlled Synthesis of ZnO Nanostructures for Caffeine Degradation and Escherichia coli Inactivation in Water

Photocatalytic and antibacterial activity of nanoparticles are strongly governed by their morphology. By varying the type of solvent used, one can obtain different shapes of ZnO nanoparticles and tune the amount of reactive oxygen species (ROS) and metal ion (Zn2+) generation, which in turn dictates their activity. ZnO nanostructures were fabricated via facile wet chemical method by varying the type of solvents. Solar light assisted photocatalytic degradation of caffeine and antibacterial activity against E. coli were examined in presence ZnO nanostructures. In addition to an elaborate nanoparticle characterization, adsorption and kinetic experiments were performed to determine the ability of nanostructures to degrade caffeine. Zone of inhibition, time kill assay and electron microscopy imaging were carried out to assess the antibacterial activity. Experimental findings indicate that ZnO nanospheres generated maximum ROS and Zn2+ ions followed by ZnO nanopetals and ZnO nanorods. As a result, ZnO nanospheres exhibited highest degradation of caffeine as well as killing of E. coli. While ROS is mainly responsible for the photocatalytic activity of nanostructures, their antibacterial activity is mostly due to the combination of ROS, metal ion, physical attrition and cell internalization.

Metal doped titania nanoparticles as efficient photocatalyst for dyes degradation

Objectives: The present work aims at the synthesis of metal-doped and undoped titania photocatalysts for the degradation of methylene blue and neutral red dyes. Methods: Un-doped and metal-doped titania photocatalysts were synthesized by hydrothermal treatment, calcined at 673 K, and were evaluated by SEM, XRD, and XPS techniques for their phase composition. Results and conclusions: XPS studies of photo catalysts confirmed the presence of transition metal ions of Co, Ni, and Zn as dopants along with titania. XRD analysis indicated that all the synthesized photocatalysts were in the anatase phase. The morphology of prepared photocatalysts was confirmed through SEM analysis. The synthesized nanoparticle’s photocatalytic nature was examined through testing their degradation potentials of methylene blue and neutral red dyes under UV light irradiation. Under optimized conditions, like pH, contact time, initial dye concentration and catalyst amount metal-doped titania photocatalysts showed higher photodegradation efficiency than the pure parental material. Among the metal doped titania best results were obtained with Ni doped titania as 90% and 95% degradation were observed for neutral red and methylene blue dyes respectively. This photocatalyst can therefore be used successfully to degrade the selected dyes present in industrial effluents.

Plant-Based Tacca leontopetaloides Biopolymer Flocculant (TBPF) Produced High Removal of Heavy Metal Ions at Low Dosage

High removal of heavy metals using plant-based bioflocculant under low concentration is required due to its low cost, abundant source, and nontoxicity for improved wastewater management and utilization in the water industry. This paper presents a treatment of synthetic wastewater using plant-based Tacca leontopetaloides biopolymer flocculant (TBPF) without modification on its structural polymer chains. It produced a high removal of heavy metals (Zn, Pb, Ni, and Cd) at a low concentration of TBPF dosage. In our previous report, TBPF was characterized and successfully reduced the turbidity, total suspended solids, and color for leachate treatment; however, its effectiveness for heavy metal removal has not been reported. The removal of these heavy metals was performed using a standard jar test procedure at different pH values of synthetic wastewater and TBPF dosages. The effects of hydroxide ion, pH, initial TBPF concentration, initial metal ion concentration, and TBPF dosage were examined using one factorial at the time (OFAT). The results show that the highest removal for Zn, Pb, Ni, and Cd metal ions were 98.4–98.5%, 79–80%, 97–98%, and 92–93%, respectively, using 120 mg/L dosage from the initial concentration of 10% TBPF at pH 10. The final concentrations for Zn, Pb, Ni, and Cd metal ions were 0.043–0.044, 0.41–0.43, 0.037–0.054, and 0.11–0.13 mg/L, respectively, which are below the Standard B discharge limit set by the Department of Environment (DOE), Malaysia. The results show that TBPF has a high potential for the removal of heavy metals, particularly Zn, Pb, Ni, and Cd, in real wastewater treatment.

Study and Determination of Aryl Hydrocarbon Receptor with Some Trace Elements in Fuel Filling Station Workers

PollutiOn is the intrOduction Of contaminantsʹ intO the natural envirOnment that cause adverseʹ change. Gasoline is a toxic and highly flammable liquid consists of various types of aliphatic hydrocarbons, olefins, benzenes and aromatic hydrocarbons including toluene, xylene and a large number of volatile compounds in addition to tetraethyl lead. Gasoline consists of different types of aliphatic hydrocarbons, aryl compounds and some trace elements. Trace elements are several important roles in human bodies, some are essential for enzymes reactions where they attract and facilitate conversion of substrate molecules to specific end products. Aryl hydrocarbon receptor (AHR) is a receptor involved in the regulation of biological responses to planar aromatic hydrocarbons.
 The aim of the present study is to compare the serum AHR level in the fuel station workers (FSW) with the non-workers as a control group. The other aim is to find out a possible correlation between AHR with trace elements.
 Sixty male FSW and 30 controls, from ten fuel stations at Al-Najaf City-Iraq, were participated in the present study. The AHR level in serum was measured using ELISA technique. Determine the following metal ions Zn2+, Cu2+, Fe3+, Mg2+, Na+ and K+ level in filling station workers (FSW) and control group were measured spectrophotometrically by using ready for use kits. Serum Pb level was carried out using Atomic absorption spectroscopy.
 The results serum concentration of AHR in FSW group revealed a significant increase (p<0.001) as compared with the control group. No significant difference was noticed in AHR as compered in exposure ≥12years with exposure <12years in FWS. Smoking has no significant correlation with other parameters. Correlation study indicated a correlation between AHR and Age. Serum concentration of Cu2+, Zn2+, K+ and Pb in FSW group revealed a significant increase (p<0.001) as compared with the control group. While Fe3+, Na+ and Mg2+ in FSW group revealed a significant decrease (p<0.001) as compared with the control group. Correlation study indicated a significant negative correlation between serum Pb and AHR while other trace elements showed no significant correlation with AHR in FSW group. There is a significant negative correlation between serum Cu2+ with age while there is significant increase correlation between Zn2+, Mg2+ and Pb with age in FWS group.
 Conclusion of study is The role of increase AHR on the health in FSW group, attention to use safety gloves and face mask is recommended for FSW and a long follow-up to the studied group is necessary to explore the prognosis of increase AHR in FSW.

Peculiarities of sol-gel synthesis of co-modified by nitrogen and metal ions (Zn2+, Zr4+, Pt2+) semiconductive TiO2 films

According to the XPS investigation of titania films co-modified by nitro gen and metal ions obtained via sol-gel method, the formation of common bonds between elements occurs due to the presence of metal ions. The mechanism of urea thermolysis is changed as a result of the ability of metal ions to form the complex compounds with urea molecules under the reported synthesis conditions that, in turn, depends on the nature of metal ions, leading to the different chemical compositions of materials’ surface. The XPS data show that nitrogen atoms are surrounded by nonmetal ones on the surface of the films modi fied by Zn2+ or Zr4+ ions. It is suggested that no formation of the complexes between Ті, Zn, or Zr atoms with urea occurs due to its protonation through an oxygen atom leading to the formation of O,N-containing reaction products. In the case of Pt2+ doping, the substitutional nitrogen incorporation in the titania lattice, as well as the formation of N-containing fragments, have been detected. The chemical nature of Pt ions allows them to interact with urea molecules through an N atom of the amino group. As a result, the transformation of urea molecules in the complexes occurs at higher temperatures concurrently with the titania crystallization that is recognized as a catalyst for the intermediates of the urea decomposition leading to the formation of common bonds between N and Ti atoms.

In neutralized medium five new Ca(II), Zn(II), Fe(III), Au(III) and Pd(II) complexity of ceftriaxone antibiotic drug: Synthesis, spectroscopic, morphological and anticancer studies

A five ceftriaxone antibiotic (ctx) complexes with Ca(II), Zn(II), Fe(III), Au(III) and Pd(II) metal ions were synthesized by 1:1 M ratio between of ceftriaxone hydrated sodium salt (Na2ctx) with CaCl2, ZnCl2, FeCl3.6H2O, AuCl3 and PdCl2 metal salts in water–methanol medium. The complexes were well characterized dependent on the microanalytical (C,H, N), molar conductance, (FTIR, Raman, 1HNMR and UV–Vis) spectroscopies, and magnetic measurements. The surface morphology and calculation of particle size of ceftriaxone complexes were performed based on SEM, TEM and X-ray diffraction. Calcium(II), zinc(II), and iron(III) complexes are six-coordinate with distorted octahedral geometry, while gold(III) and palladium(II) are four-coordination mode. The ceftriaxone drug acts as a tetradentate ligand towards five metal ions through N (amino group) and O (triazine, β-lactam carbonyl, and carboxylate groups) with the molecular formulas [Ca(ctx)(H2O)2].5H2O (1), [Zn(ctx)(H2O)2].7H2O (2), [Fe(ctx)(H2O)(Cl)].7H2O (3), [Au(ctx)].Cl. 4H2O (4) and [Pd(ctx)].3H2O (5). The cytotoxicity assays study of gold(III) complex against colon carcinoma cells (HCT-116) and hepatocellular carcinoma cells (HepG-2) showed that the 50% inhibitory concentration (IC50) of [Au(ctx)].Cl.4H2O against HepG-2 cell line is 8.53 μg higher than that of HCT-116 cell line 20.5 μg.

Preparation, spectroscopic and anticancer studies of metal antibiotic Chelation Ni(II), Cu(II) and Zn(II) 4,5-dimethyl Thiazolylazo complexes

This work included synthesis of new ligand 2-[2-(4,5-Dimethyl thiazolyl)azo]-4,6-dimethyl phenol (DMeTADMeP) by coupling of diazonium salt of 2-amino-4,5-dimethyl thiazole with (2,4-dimethylphenol). Also, preparation of new series of chelate complexes of Ni(II), Cu(II) and Zn(II) metal ions were also prepared by mixing solution of metal salts with solution of ligand at mole ratio[ M:L] [1:2] for Ni(II), Cu(II) and Zn(II) metal ions. The structures of the azo dye ligand and its metal complexes were confirmed by various analytical techniques like by UV-visible, FT-IR, Mass spectroscopic, 1H-NMR, 13C-NMR, (C.H.N.S) element analyses, molar conductance, FESEM and XRD diffraction studies. The antibacterial and antifungal activity of thiazolyl azo dye and its metal complexes were shown activity towards both bacterial Escherichia coli (gram negative), streptococcus (gram positive) and Penicillium as antifungal. The results shows that this kind of compounds plays an important role in the rate of inhibition of the growth of bacterial. The anticancer activity was also conducted of the (DMeTADMeP) and Cu(II)-complex by cells cytotoxicity and screen for in vitro antitumor activity against human Hepatocellular cancer. The results indicated that this type of this compounds play an important role in the rate of inhibition of the growth cells of cancerous, undoubtedly the possibility of using them as anti-cancer drugs in the field of medicine and pharmacy.

Biogenic and chemically synthesized Solanum tuberosum peel\u2013silver nanoparticle hybrid for the ultrasonic aided adsorption of bromophenol blue dye

This work was aimed at the synthesis of a hybrid (STpe-AgNP), obtained by impregnation of silver nanoparticles (AgNP) onto Solanum tuberosum peel (STpe), for the ultrasonic assisted adsorption of bromophenol blue (BB) dye. SEM, FTIR, XRD, EDX, TGA and BET techniques were used to characterize the adsorbents. The XRD, SEM and EDX confirmed successful impregnation of AgNPs onto STpe to form the hybrid. The AgNPs impregnated onto the hybrid were found to be water stable at various pH values of 2.0–9.0. Chi-square (χ2 < 0.024) and linear regression (R2 > 0.996) showed that the Freundlich model was best fitted among the isotherm models, corroborated by the oriented site model. Kinetic analysis conformed to the intraparticle diffusion and pseudo-first-order rate equations, while thermodynamics displayed a physical, spontaneous and endothermic adsorption process. The presence of competing Pb(II), Ni(II), Cd(II) and Zn(II) metal ions in solution interfered with the adsorption of BB onto the biosorbents. In terms of reusability, STpe and STpe-AgNP showed BB desorption of 91.3% and 88.5% respectively, using NaOH as eluent. Ultra-sonication significantly enhanced the adsorption of BB by both adsorbents, but the impregnation of AgNPs only slightly improved adsorption of the dye from the simulated wastewater. This study also illustrated that pristine STpe biomass waste is a cheap viable option for the decontamination of BB from water.

A novel dimer-induced AIE material as a nano-sensor for colormetric and ratiometric sensing of Erythromycin and metal ions (Zn2+, Cd2+ and Cu2+) with different dissociation and re-aggregation processes and cellular imaging applications

We reported a sensor BZH bearing AIE (aggregation-induced emission) characteristics in solid state and aqueous ethanol solution. In EtOH/H2O (1/9, V/V) medium, BZH possessed spherical shape with the average diameter of ~142 nm due to the unique dimer formation by intermolecular hydrogen bonds, and exhibited fluorescence ratiometric response to Erythromycin, Zn2+ and Cd2+ and UV–vis ratiometric behavior to Cu2+ along with remarkable naked-eye color changes, respectively. The binding stoichiometry of BZH to Erythromycin was 2:1, but that to metal ions was 1:1. The BZH towards Erythromycin and metal ions showed different sensing mechanisms, and were confirmed by job'plot, 1H NMR FT-IR, ESI-MS, DLS and TEM. The presence of Erythromycin triggered the ESIPT process and induced new intramolecular hydrogen bond formation, but the presence of metal ions (Zn2+, Cd2+ and Cu2+) caused deprotonation processes, these caused the BZH dimers' dissociation and consequently induced monomer emission. Meanwhile, the morphology of BZH changed from spherical to flower shape for Erythromycin and block shape for metal ions, indicating the Erythromycin and metal ions with BZH monomer further formed new aggregates, respectively. Furthermore, the BZH was applied to detect Erythromycin, Zn2+, Cd2+ and Cu2+ in actual water samples and Hela cells.

Water soluble Cu(II) and Zn(II) complexes of bidentate-morpholine based ligand: synthesis, spectral, DFT calculation, biological activities and molecular docking studies

Copper(II) and zinc(II) complexes of the type [ML(AcO)2.H2O] were synthesized from bidentate-morpholine based Schiff base ligand (L - morpholinopropylimino)methyl)-6-methoxyphenol). The prepared ligand, copper(II) and zinc(II) complexes were characterized by elemental analysis, ESI-MS, 1H-NMR, FT-IR, UV-Visible, ESR and spectrometric methods. The elemental and ESI-MS results have been established that the prepared ligand and complexes possess 1:1 stoichiometric ratio. 1H-NMR and FT-IR results have been suggested that azomethine nitrogen and morpholine ring nitrogen atoms are coordinated with Cu(II) and Zn(II) metal ions. UV-Visible, ESI-MS and ESR spectroscopic results have been supported that the proposed structure of Cu(II) and Zn(II) complexes possess square pyramidal geometry. In order to confirm the proposed square pyramidal geometry of prepared complexes by DFT calculation has been studied. DNA binding ability of Cu(II) and Zn(II) complexes have been studied by electronic absorption and viscometric methods. These results reveal that Cu(II) and Zn(II) complexes interact with CT-DNA by the way of groove binding mode. Molecular docking studies result shows that synthesized compounds has better binding ability. The in vitro antioxidant activities of ligand, Cu(II) and Zn(II) complexes have been investigated by using the DPPH assay. The result shows that synthesized compounds have good radical scavenging activity against DPPH radical. Antimicrobial activities of synthesized ligand and its complexes have been tested against selected bacterial (gram positive & gram negative) and fungal species. The results reveal that Cu(II) and Zn(II) have good antimicrobial activity than ligand. Communicated by Ramaswamy H. Sarma