In this study, eco-friendly casein-copper hybrid nanoflowers (CAS-Cu HNFs) were synthesised and their applicability for the removal of Pb(II) and Cd(II) ions was investigated. Hybrid nanoflowers were synthesised by adding CuSO4 solution on casein in PBS medium. According to the evaluation of SEM images, regular nanoflower structures were obtained after the addition of 40 mu L of 100 mM CuSO4 and 12 h incubation. Characterisation studies were performed by XRD, SEM-EDX, FTIR and TGA. The effects of contact time, pH, temperature and heavy metal ion concentration on the adsorption performance were investigated. Optimum adsorption was achieved at 60 min contact time and 35 and 30 degrees C for Pb(II) and Cd(II) ions, respectively. The performance of CAS-Cu HNFs was evaluated by linear and non-linear forms of adsorption isotherms and adsorption kinetics, respectively. The linear Langmuir isotherm model showed compatibility and the maximum adsorption capacity was found to be 769.23 and 156.25 mg/g for Pb(II) and Cd(II) ions, respectively. CAS-Cu HNFs has great potential as an eco-friendly, nanoscale, flower-like, organic-inorganic hybrid nano-flower adsorbent for the effective removal of Pb(II) and Cd(II) ions from aqueous solutions.

In this study, chitosan-nanoclay composite beads (CS/NC composite beads) were used to remove Ponceau S from aqueous solutions. CS/NC composites characterization was performed with FTIR, SEM-EDX, TGA, BET and XRD analyzes. The adsorption procedure was optimized by changing various parameters in batch experiments such as pH, dye concentration, contact time and temperature. Ponceau S adsorption took place at a higher rate in the acidic region, and the highest adsorption was observed at pH 2.0. The amount of adsorbed dye increased as the temperature increased at low dye concentrations and the time required to reach equilibrium was shorter than at higher dye concentrations. Linear and non-linear forms of Langmuir, Freundlich and Temkin adsorption models were applied. The adsorption behavior of Ponceau S is compatible with the linear Langmuir model, and the maximum adsorption capacity was found to be 140.85 mg g-1. Linear and nonlinear forms of adsorption kinetics and thermodynamic parameters were investigated for dye concentrations of 150-400 mg/L. The adsorption kinetics fit the linear pseudo-second-order kinetic model and the Ponceau S adsorption on CS/NC composites was spontaneous and endothermic. The results show that the CS/NC composites can be used as an effective adsorbent in industrial wastewater treatment.

In this study poly(N-vinylimidazole-acrylamide) p(N-VI-AAm) hydrogels were prepared as an adsorbent for adsorptive removal of lead (II) and copper (II) ions from aqueous solution. Adsorption studies showed that poly(N-vinylimidazole-acrylamide) p(N-VI-AAm) hydrogels can be effectively used to remove heavy metals. Hydrogel characterization was done by FTIR and SEM. The effect of the removal conditions such as contact time, pH, temperature, and initial metal ion concentration on the Pb (II) and Cu (II) ions binding was also tested. Maximum adsorption was achieved at 30 degrees C and 35 degrees C for Pb (II) and Cu (II) after 24 h, respectively. Experimental capacities were calculated as 262 and 53 mg g(-1) for lead and copper, respectively. The isotherms were analyzed with Langmuir and Freundlich models. Briefly, this economic and high adsorption performance poly(N-VI-AAm) hydrogel is a promising candidate for sewage disposal and metal pollution treatment.

Poly(N-vinylimidazole-ethylene glycol dimethacrylate (poly(N-VI-EGDMA)) and poly(2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate (poly(HEMA-EGDMA)) were synthesized as adsorbents for adsorptive removal of tartrazine dye from aqueous solutions. To achieve maximum tartrazine adsorption, some parameters were examined and pH was found to be an important factor on adsorption poly(N-VI-EGDMA). As the temperature increased, removal amount of tartrazine was increased. The experimental capacities were found as 265.5 mg/g and 45.15 mg/g for poly(N-VI-EGDMA) and poly(HEMA-EGDMA), respectively. The experimental data well correlated with Freundlich isotherm. The estimated ∆Hº values were found as 12.76 kJ/mol and 10.40 kJ/mol for poly(N-VI-EGDMA) and poly(HEMA-EGDMA), respectively. Adsorption was demonstrated to be endothermic in nature. The characterization of these polymers were done by using FTIR, TGA and SEM analysis.

In the present work, selective adsorption of β-glucosidase using imprinted polyacrylamide hydrogels were studied. For this purpose imprinted hydrogels were prepared using β-glucosidase as a template molecule, acrylamide (AAm) as a monomer, N,N’- methylenebisacrylamide (MBAA) as a crosslinker, ammonium persulphate (APS) and N,N,N’,N’-tetramethylethylene-diamine (TEMED) as initiators. β-Glucosidase imprinted hydrogel was washed with a solution of sodium dodecyl sulfate (SDS) and acetic acid to remove the template molecule. Non-imprinted hydrogel was also prepared without using β-glucosidase template. The adsorption and recognition performance of hydrogels towards β-glucosidase was discussed through adsorption isotherms and adsorption kinetics. In batch template rebinding experiments, imprinted hydrogels displayed quite high template binding capacity than non-imprinted hydrogels. The theoretical maximum adsorption capacity (Qmax) was determined by the Langmuir model, which turned out to be 7.2 mg/g and 4.6 mg/g for imprinted and non-imprinted hydrogels respectively. A pseudo-second-order model was suitable to interpret kinetic data.

Eggshell membrane (ESM) was used as an adsorbent for adsorption of reactive red 195 (RR195) and reactive black 5 (RB5) dyes from aqueous solutions. The experimental conditions were optimized via batch system experiments for maximum azo dyes removal. Adsorption of the dyes was pH dependent highly, and the maximum adsorption of RR195 and RB5 occurred at pH 3.0 and 2.0, respectively. For both dyes, the adsorption process was seen to be obeyed pseudo-second order kinetic and the Langmuir isotherm models. Maximum adsorption capacities (Qmax) of ESM for RR195 dye and RB5 were found as 76.9 and 333.33 mg g-1, respectively. The thermodynamic parameters were calculated and the adsorption of the dyes was found to be as exothermic and spontaneous. Moreover, the structural characterization of the ESM was performed by FTIR and SEM analysis.

A novel, chitosan coating on the surface of magnetite (Fe3O4) (erythrosine-imprinted magnetic chitosan (EIMC)) was successfully synthesized using erythrosine (ER) as a template for adsorption and the removal of ER from aqueous solutions. Characterization of the obtained EIMC was achieved by FTIR spectra, SEM micrographs, and TGA analysis. Batch adsorption experiments of EIMC and non-imprinted magnetic chitosan (NIMC) were performed to investigate the adsorption conditions. The results showed that the maximum adsorption capacity for EIMC and NIMC was observed at pH 6 and temperature 40 degrees C. Equilibrium adsorption was achieved within 3 h. Adsorption process could be well described by Freundlich adsorption isotherms. Thermodynamic parameters namely Delta G degrees, Delta H degrees, and Delta S degrees of the ER adsorption process were calculated. The negative values of Gibbs free energy of adsorption (Delta G degrees) indicated the spontaneity of the adsorption of ER dye on the EIMC and NIMC. Desorption of ER from EIMC and NIMC could be done rapidly using 0.1 M NaOH solution and the beads could be used again to remove ER. Results show that imprinting technique increases the removal amount of ER dye from aqueous solutions.

β-Glucosidase was covalently immobilized on chitosan-MWCNTs carrier and its aroma enhancement effect in different tea samples was investigated. Chitosan-MWCNTs carrier was prepared by mixing chitosan with MWCNTs (5:1 w/w) and characterization of prepared composite carrier was done by FTIR, TGA and SEM analysis. β-Glucosidase was covalently immobilized on the composite carrier after glutaraldeyde activation. After optimization of the immobilization conditions, immobilization yield was achieved as 95.22%. Optimum pH was found as pH 6.0 and pH 5.0 for free and immobilized enzyme, respectively. Optimum temperature of the enzyme was shifted from 35 °C to 45 °C after immobilization. The Km and Vmax values for immobilized β-glucosidase calculated as 5.55 mM and 7.14 U/mg protein respectively. Immobilized β-glucosidase showed better pH and storage stability than free enzyme. After storage at +4 °C for 50 days, the immobilized enzyme retained its 68.4% of the initial activity. The calculated half-life (t1/2) of immobilized enzyme was 115.8 min. After 10 cycles of reuse, immobilized β-glucosidase showed 72.83% of its initial activity.

The preparation and characterization of poly(methyl methacrylate-ethylene glycol dimethacrylate), (poly(MMA-EGDMA)) polymer for erythrosine adsorption has been investigated. Erythrosine is a synthetic red dye used to color food. Water-soluble acid dyes have caused serious water pollution. Poly(MMA-EGDMA) polymer showed better adsorption performance for erythrosine at acidic region and at 30 degrees C. The adsorption process had also been verified by Langmuir and Freundlich adsorption isotherms at 30, 40, and 50 degrees C. Free energy of adsorption ( increment G degrees), enthalpy ( increment H degrees), and entropy ( increment S degrees) changes were calculated to predict the nature of adsorption. The estimated value for increment G degrees was calculated as -125.6 kJ/mol at 303 K (30 degrees C). The estimated value for increment H degrees was found as -60.69 kJ/mol at 303 K. The negative value for increment H degrees indicated that the adsorption of erythrosine on poly(MMA-EGDMA) polymer was an exothermic process.

An on-line flow injection preconcentration-flame atomic absorption spectrometry (FI-AAS) method is developed for trace determination of chromium(III) by sorption on a mini-column packed with epichlorohydrin (ECH) crosslinked chitosan-clay composite beads. The factors affecting preconcentration of Cr(III) ions such as sample and eluent flow rate, loading time, sample and eluent pH, and eluent type and concentration were investigated. The Cr(III) ions were eluted from the mini-column with 0.1 M EDTA. Under the optimized parameters, the calibration graph using the preconcentration system for Cr(III) was linear with a correlation coefficient of 0.9982. Detection and quantification limits of the method were obtained to be 0.0162 and 0.0929 mu gmL(-1) respectively, with an enrichment factor of 13.4.

Endüstrilerin hızlı gelişmesiyle ağır metaller doğrudan veya dolaylı olarak özellikle gelişen ülkelerde çevreye bırakılmakta ve bunun sonucu olarak çevre kirliliği ortaya çıkmaktadır. Su kirliliği, çevre kirliliğinin önemli bir parçasını oluşturmaktadır. Metaller sulu ortamda yüksek çözünürlüğe sahip olduklarından yaşayan organizmalar tarafından adsorbe edilebilir. Ağır metallerin çoğu canlı organizmalar için gerekli olmakla birlikte belirli bir konsantrasyonun üzerinde enzim sistemlerinin inhibisyonuna neden olmaktadır. Ni (II) ve onun çeşitli bileşikleri çeşitli endüstrilerde yaygın bir şekilde kullanılır. Elektro kaplama, boya ve baskı nikel içeren ve atık oluşturan proseslerdir [1].

Catalase was immobilized on chitosan and modified chitosan. Studies were carried out on free-immobilized catalase concerning the determination of optimum temperature, pH, thermal, storage stability, reusability, and kinetic parameters. Optimum temperature and pH for free catalase and catalase immobilized were found as 35°C and 7.0, respectively. After 100 times of repeated tests, the immobilized catalases on chitosan-clay and magnetic chitosan maintain over 50% and 60% of the original activity, respectively. The ease of catalase immobilization on low-cost matrices and good stability upon immobilization in the present study make it a suitable product for further use in the food industry.

A simple and effective biodegradable material known as chitosan-clay composite beads were prepared to remove Pb(II) ions from aqueous solution. For this purpose, various important parameters such as contact time, pH and temperature were examined on the adsorption of Pb(II) ions onto crosslinked chitosan-clay composite beads. Maximum adsorption capacity of Pb(II) was observed at pH 4.5 and 25 degrees C and calculated as 7.93 mg/g according to Langmuir isotherm model. Thermodynamic parameters namely Delta G degrees, Delta H degrees and Delta S degrees of the Pb(II) adsorption process have been calculated as 7.889 kJ/mol, -15.131 kJ/mol and -0.0785 kJ/molK respectively. EDTA was the best eluent for the desorption of Pb(II) ions from the crosslinked chitosan-clay beads. Scanning electron microscope (SEM) was used to characterize the surface morphology of the crosslinked chitosan-clay beads.

Tyrosinase was immobilized on glutaraldehyde crosslinked chitosan–clay composite beads and used for phenol removal. Immobilization yield, loading efficiency and activity of tyrosinase immobilized beads were found as 67%, 25% and 1400U/g beads respectively. Optimum pH of the free and immobilized enzyme was found as pH 7.0. Optimum temperature of the free and immobilized enzyme was determined as 25–30°C and 25°C respectively. The kinetic parameters of free and immobilized tyrosinase were calculated using l-catechol as a substrate and Km value for free and immobilized tyrosinase were found as 0.93mM and 1.7mM respectively. After seven times of repeated tests, each over 150min, the efficiency of phenol removal using same immobilized tyrosinase beads were decreased to 43%.

An inhibition based biosensing system was developed for the caffeic acid as lipoxygenase (LOX) inhibitor. LOX was immobilized in carbon paste electrode and the amperometric detection of hydroperoxy linoleic acid due to the enzymatic reaction using linoleic acid as a substrate was monitored at +0.9 V versus Ag/AgCl. The decrease in biosensor response in the presence of caffeic acid was found to be correlated with the inhibitor concentration. Diode array detector and LOX biosensor was used as an electrochemical detector for the analysis of this compound. All data were given as a comparison of two systems.

In order to increase the nickel adsorption capacity of raw chitosan beads (CB), they were chemically modified with histidine (HIS-ECH-CB) by using crosslinking agent, epichlorohydrine (ECH). The nature and morphology of the sorbent were characterized using FTIR, TGA and SEM analysis. For optimization of adsorption conditions, sorption experiments were performed by varying contact time, pH, temperature and initial nickel concentration. Based on the adsorption experiment, the HIS-ECH-CB showed the significant adsorption capacity of 55.6 mg/g under the optimal adsorption condition. Nickel adsorption isotherms data were fitted to Freundlich isotherm. Thermodynamic parameters namely Delta G degrees. Delta H degrees and Delta S degrees of the Ni(II) adsorption process were calculated. The negative values of Gibbs free energy of adsorption (Delta G degrees) indicated the spontaneity of the adsorption of Ni(II) ions on the histidine modified chitosan. Desorption of Ni(II) ions from HIS-ECH-CB could be done rapidly by using 0.1 M HCl, HNO3 and EDTA solutions and the beads could be used again to adsorb Ni(II) ions. (C) 2012 Elsevier B.V. All rights reserved.

Removal of Ni(II) and Cd(II) by adsorption on epichlorohydrin crosslinked chitosan-clay composite beads was examined in solutions representative of contaminated solutions containing heavy metals. Several important parameters influencing the adsorption of Ni(II) and Cd(II) ions such as contact time, pH, temperature and effect of metal concentration were investigated systematically by batch experiments. Langmuir and Freundlich adsorption models were used to describe adsorption isotherms and constants. The obtained results showed that the equilibrium adsorption behavior of Ni (II) and Cd (II) on epichlorohydrin crosslinked chitosan-clay composite beads could be applied to Langmuir and Freundlich models respectively. Maximum adsorption capacities for Ni(II) and Cd(II) ions were found as 32.36 mg g(-1) and 72.31 mg g(-1) respectively. The recovery of the metal ions after adsorption and the regeneration of the adsorbent was carried out by treatment of the loaded beads with either 0.1 M HNO3, or 0.01 M EDTA. The adsorbents were characterized by FTIR, SEM and TGA analysis. (C) 2012 Elsevier B.V. All rights reserved.

Glutathione imprinted polymer was prepared using 1-vinyl imidazole and ethylene glycol dimethacrylate as the functional monomer and crosslinker, respectively, in dimethyl sulfoxide. The adsorption selectivity of glutathione-imprinted polymer was tested by reduced glutathione, oxidized glutathione, and L-Gly-Leu-Tyr in 30% phosphate buffer (0.01 M, pH 5.0)–70% acetonitrile and binding affinity values were compared. Reusability of molecularly imprinted polymer particles was also investigated. Molecularly imprinted polymer particles were found to be stable and to maintain glutathione adsorption capacity at 95% when washed with methanol–acetic acid (10%) after seven usages. Functional monomer 1-vinyl imidazole and cross linker ethylene glycol dimethacrylate-based glutathione imprinted polymer could be used as solid phase extraction material for recognition of glutathione in biological samples.

BACKGROUND:Type 2 diabetes is a complex disease that still requires a great deal of work to be carried out to understand the pathophysiology. Recently, researchers have focused on studying the organs and tissues known to be involved in the development of the type 2 phenotype using a proteomic approach. Little work has been reported on plasma of type 2 diabetics in whom the clinical status has been well characterized. In this study, changes in plasma proteins of type 2 diabetics were investigated by proteomic analysis in well-characterized individuals with type 2 diabetes (early and late stage) and control groups (with or without a family history of diabetes).METHODS:Samples were analysed by two-dimensional gel electrophoresis and significantly differentiated proteins were identified by nano-LC-ESI-MS.RESULTS:A total of 12 protein signatures that were differentially displayed with high significance compared with controls were selected. Four of the differentially displayed proteins were identified as haptoglobin alpha2, haptoglobin Hp2(fragment) and transthyretin and Chain A (formerly prealbumin), and all were up-regulated. Thiol-specific antioxidant protein, Chain A, tertiary structures of three amyloidogenic transthretin variants and haptoglobin-related protein precursor were all down-regulated in controls with a family history of diabetes, early and late diabetic patients in comparison with the control.CONCLUSION:A proteomic-based approach was used to discover and identify the differentially expressed proteins in various states of type 2 diabetes.