Immobilization Of Β-cyclodextrin Research Articles

Immobilization of β-cyclodextrin onto the surface of electrospun fibers as rapid and highly efficient adsorbent with good recyclability

It is still a big challenge to obtain adsorbents with high adsorption rate and improved adsorption capacity. Herein, we report a novel electrospun fibers adsorbent modified with carboxylated-β-cyclodextrin (CB-β-CD) molecules for the rapid and efficient removal of phenolphthalein (PHP) from water. First, CB-β-CD is synthesized by esterification of β-CD with succinic anhydride. Subsequently, by means of polydopamine (PDA) coating rich in amine groups, CB-β-CD is covalently bonded onto the surface of poly(vinylidene fluoride)@polystyrene/PDA (PVDF@PS/PDA) fibers through the amide linkage to obtain PVDF@PS/PDA/CB-β-CD fibers adsorbent. XPS, WCA and thermal properties results suggest that large amounts of CB-β-CD molecules hang over the surface of PVDF@PS/PDA/CB-β-CD fibers and the cavities of CB-β-CD molecules are well preserved, thus providing more sites to form inclusion complexes with guest molecules. The adsorbent exhibits excellent adsorption properties for PHP, with a saturation adsorption capacity of 39.97 mg/g after 10 min, which is superior to other reported adsorbents containing β-CD. Moreover, PVDF@PS/PDA/CB-β-CD shows good recyclability and highly selective adsorption of PHP, which has potential applications in molecular recognition, organic molecules separation, and water purification. The developed method provides a new strategy for immobilizing more β-CD molecules onto the surface of composite materials to endow superior comprehensive performances.

Immobilization of β-cyclodextrin onto polypropylene nonwoven fabric based on photooxidative surface modification

Immobilization of β-cyclodextrin onto polypropylene nonwoven fabric based on photooxidative surface modification

Adsorptive removal of cholesterol by biodegradable zein-graft-β-cyclodextrin film

A novel bio-based zein-graft-β-cyclodextrin film was synthesized for cholesterol adsorption at room temperature. Immobilization of β-cyclodextrin (β-CD) to zein was achieved by the Maillard reaction and the zein-graft-β-CD powders showed higher glass transition temperature and higher solubility in water. Zein-graft-β-CD films, prepared by solvent evaporation casting, showed excellent capacity for cholesterol adsorption. The F1:1 has the best adsorption properties, and the maximum adsorption capacity can reach 5.70 ± 0.56 mg cholesterol/g film. The adsorption cholesterol mechanism of zein-graft-β-CD film was correspond to the pseudo-first order kinetic model. In addition, the zein-graft-β-CD film retained an adsorption capacity of 3.10 ± 0.89 mg cholesterol/g film after three reuses. Using composite enzyme (1 mg/mL papain and 1 mg/mL amylase), the film (F1:1) degradation reached 98.81% in 1 week. These results suggest that zein-graft-β-CD film has potential as a nature-based adsorbent for cholesterol adsorption and could be used in the food industry.

A chiral sensor for recognition of DOPA enantiomers based on immobilization of β-cyclodextrin onto the carbon nanotube-ionic liquid nanocomposite

A sensitive electrochemical method was explored for chiral recognition of 3,4-dihydroxyphenylalanine (DOPA) enantiomers based on immobilization of β-cyclodextrin (β-CD) onto the nanocomposite comprising multiwalled carbon nanotubes (MWCNTs) and ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate (BIMIMPF6) modified glassy carbon electrode (β-CD/MWCNTs-IL/GCE). The combination of ionic liquid and carbon nanotubes could create unique nanomaterials which facilitated the electron transfer. In addition, β-CD was brought in to act as the chiral selector for DOPA enantiomers recognition. The immobilization process of β-CD/MWCNTs-IL/GCE was monitored by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The chiral interface (β-CD/MWCNTs-IL/GCE) was employed to discriminate DOPA enantiomers via differential pulse voltammetry. The results indicated that the proposed sensor exhibited a stronger electrochemical response toward D-DOPA over the linear range from 4.0 × 10−3 to 4.0 × 10−9 mol L−1 and the detection limit was 1.2 × 10−9 mol L−1 (S/N = 3). This work provided an available platform for enantioselective recognition of DOPA enantiomers based on the nanocomposite.

Nanoporous functional organosilicas for sorption of toxic ions

The chemical immobilization of β-cyclodextrin and its bromoacetyl and thiosemicarbazidoacetyl functional derivatives on the surface of highly disperse amorphous nanoporous silica was performed. β-Cyclodextrin-containing silicas were found to have high affinity to mercury(II), cadmium(II), and zinc(II) cations. Supramolecular surface structures formed whose chemical composition depends on the nature of the sorbed cations and the functional substituents in the attached β-cyclodextrin molecules.

Recent Advances in the Immobilization ofβ-Cyclodextrin and Their Application

Recent Advances in the Immobilization of<i>β</i>-Cyclodextrin and Their Application

Application of β-cyclodextrin in polymeric solid phase for separation and determination of lead in different environmental matrices

Immobilization of β-cyclodextrin on Dowex resin as an insoluble polymeric matrix by covalent bond presents a new solid-phase medium for preconcentration of Pb (II) at trace level in environmental samples prior to its flame atomic absorption spectrometric determination. The method is based on the sorption of lead after passing on modified Dowex sorbent in a column. The effect of several parameters such as pH, flow rate of sample, eluent kind and volume was investigated. The sorption capacity of the matrix has been found to be 0.4996 mg g−1 of adsorbent with the preconcentration factor of 250 for Pb (II). Nitric acid (3 M) as an eluent was sufficient to obtain quantitative recovery (>95%) for Pb (II). The optimum flow rate was 10 ml min −1. The calibration curve was linear in the range of (3–250 ng mL−1) with a correlation coefficient of 0.9995. The limit of detection (LOD) based on three times the standard deviation of the blank was 1.37 ng mL−1. The relative standard deviation (RSD) for determination of 10 ng mL−1 and 100 ngmL−1 of Pb (II) was 3.00 % and 0.58 % (n = 10), respectively. The method was successfully applied to determination of lead in some environmental samples such as tap water, river water, soil and rice.

Immobilization of β-Cyclodextrin as Insoluble β-Cyclodextrin Polymer and Its Catalytic Performance

Insoluble β-cyclodextrin polymers were prepared from β-cyclodextrin (β-CD) using epichlorohydrin (EPI) as crosslinking agent under basic conditions. The polymers were characterized by Fourier Transform Infrared (FTIR), Thermogravimetry (TG), X-ray diffraction (XRD) and TG-FTIR. The results demonstrated that the polymerization between EPI and β-CD indeed occurred, and a number of CD rings were interconnected to form a three-dimensional network. Moreover, different factors influencing the polymerization, e.g. molar ratio of EPI to β-CD, the concentration of NaOH and reaction temperature, have been investigated. The polymer prepared under the optimal conditions (the molar ratio EPI: β-CD of 44, the NaOH concentration 50% in mass, and the temperature at 65 °C) showed excellent thermal stability and insolubility in organic solvents or strong acid/base. In addition, the β-cyclodextrin polymers also presented high catalytic activity for aqueous oxidation of benzyl alcohol with hypochlorite as oxidant.

Immobilization of β-cyclodextrin in ethylene-vinyl alcohol copolymer for active food packaging applications

Abstract Current developments in active food packaging are focusing on incorporating agents into the polymeric package walls that will release or retain substances to improve the quality, safety and shelf-life of the food. Because cyclodextrins are able to form inclusion complexes with various compounds, they are of potential interest as agents to retain or scavenge substances in active packaging applications. In this study, β-cyclodextrin (βCD) was successfully immobilized in an ethylene-vinyl alcohol copolymer with a 44% molar percentage of ethylene (EVOH44) by using regular extrusion with glycerol as an adjuvant. Films with 10%, 20% and 30% of βCD were flexible and transparent. The presence of the agent slightly increased the glass-transition temperature and the crystallinity percentage of the polymer, that is to say, it induced some fragility and a nucleating effect. The water vapor, oxygen and carbon dioxide barrier properties of the materials containing βCD were determined and compared with those of the pure polymeric material. Permeability to these three permeants increased with the addition of βCD due to the presence of discontinuities in the matrix and to the internal cavity of the oligosaccharide. Also the CO 2 /O 2 permselectivity increased with the addition of βCD. Finally, the potential effect of the composites in the food aroma was analyzed. The materials with βCD preferentially sorbed apolar compounds such as terpenes. This characteristic could be useful in active packaging applications for preferentially retaining undesired apolar food components like hexanal or cholesterol.

Influence of the surface structure of β-cyclodexrin-containing silica on the adsorption of mercury nitrate from dilute solutions

The construction of adsorption sites for mercury(II) by chemical immobilization of β-cyclodextrin and its functional derivatives on a surface of macroporous amorphous silica is proposed. It is shown that the adsorption of mercury(II) is adequately described by the Langmuir isotherm equation for monolayer adsorption on localized sites of energetically homogeneous surfaces. It is established that the considerably increased sorption of mercury nitrate on silica modified by different β-cyclodextrins is due to the formation of 1: 1 β-cyclodextrin-nitrate ion inclusion complexes on the surface and the participation of side functional groups of the upper edge of immobilized β-cyclodextrin molecules in the formation of mixed-ligand mercury(II) complexes.

Immobilization of β-cyclodextrin onto Dowex resin as a stationary microvessel and phase transfer catalyst

Abstract In this study, immobilization of β-cyclodextrin onto commercial Dowex resin by covalent bond was reported. The efficiency of this biocatalyst system as a stationary microvessel and new solid–liquid phase transfer catalyst in reduction of epoxides by NaBH 4 was studied.

Immobilization of β-cyclodextrin on gold surfaces by chemical derivatization of an 11-amino-1-undecanthiol self-assembled monolayer

A new methodology for the covalent functionalization of a SAM of 11-amino-1-undecanethiol, previously adsorbed on polycrystalline Au, was successfully applied in order to immobilize a β-CD layer on surface. A two steps synthetic strategy is proposed based on the activation of the SAM with di-(N-succinimidyl) carbonate for the further inclusion of the β-CD. The modification of the SAM was followed by PM-FTIRRAS, AFM imaging, CV, and EIS which confirmed the introduction of β-CD layer. The AFM images allowed the identification of homogeneously distributed β-CD aggregates over the Au grain microstructure. The electrode was characterized in the presence of electroactive species in solution, with the ability to form inclusion complexes with the β-CD cavity. Contrary to the reported for other thiolated CD derivative films, the results of this study showed the formation of well-packed and compact structures which strongly reduce non-specific adsorption phenomena. The redox response of the probes at the β-CD electrode was shown to appear at higher potentials with respect to the response at bare Au. Good correlation was found between the increase of the hydroquinone oxidation peak and, both, the scan rate used in CV experiments (typical behavior of surface-confined species) and the hydroquinone concentration. In the case of dopamine, the processes seem to shifted out of the potential window of SAM stability. The results suggest that this problem could be overcome by improving the design of the device.

Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of β-cyclodextrin

Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with γ rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. β-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of β-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

Oxygen plasma-treated gold nanoparticle-based field-effect devices as transducer structures for bio-chemical sensing

EIS (electrolyte-insulator-semiconductor) sensors based on the functionalization of uncoated gold nanoparticles supported on a Si/SiO2 structure are presented. Oxygen plasma etching at moderate power (<200 W) provides a convenient and efficient way to remove organic capping agents from the gold nanoparticles without significant damage. Higher power intensities destroy the linkage between the SiO2 and the gold nanoparticles, and some of the gold nanoparticles are removed from the surface. The flat-band potential shift, i.e. the pH dependence of the gold-coated EIS sensors is similar (33 mV/pH) to the uncoated EIS pH-sensor. Lead, penicillin and glucose sensors were prepared by immobilization of β-cyclodextrin, penicillinase and glucose oxidase by various immobilization techniques.

Immobilization of β-Cyclodextrin on Silica Gel

Abstract β-Cyclodextrin (β-CyD) was covalently immobilized on silica gel by chlorination of silica gel with thionyl chloride or silicon tetrachloride, followed by the reaction of the resulting chlorinated silica gel with β-CyD in pyridine. The amounts of the immobilized β-CyD were 8×10−5 to 1.4×10−4 mol per 1 g of the β-CyD–silica gel composites. On heating, the composites did not exhibit weight decrease up to 250 °C. The β-CyD in the composites formed 1 : 1 complex with phenol in aqueous solutions, and the equilibrium constant for the dissociation of the complex was 6×10−3 mol dm−3 at 25 °C. The immobilized β-CyD exhibited catalytic activity in the cleavage of 4-nitrophenyl acetate at 25 °C, pH 8.7.