Epichlorohydrin Concentration Research Articles

Optimized design of quaternary amino-functionalized chitosan fibers for ultra-high diclofenac adsorption from wastewater

The extraction of non-steroidal anti-inflammatory drugs (NSAIDs) from water bodies is imperative due to the potential harm to humans and the ecosystem caused by NSAID-contaminated water. Quaternary amino-functionalized epichlorohydrin cross-linked chitosan fibers (QECFs), an economical and eco-friendly adsorbent, were successfully prepared using a simple and gentle method for efficient diclofenac (DCF) adsorption. Additionally, the optimized factors for the preparation of QECFs included epichlorohydrin concentration, pH, temperature, and (3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHTAC) concentration. QECFs demonstrated excellent adsorption performance for DCF across a broad pH range of 7–12. The calculated maximum adsorption capacity and the amount of adsorbed DCF per adsorption site were determined to be 987.5 ± 20.1 mg/g and 1.2 ± 0.2, respectively, according to the D-R and Hill isotherm models, at pH 7 within 180 min. This performance surpassed that of previously reported adsorbents. The regeneration of QECFs could be achieved using a 0.5 mol/L NaOH solution within 90 min, with QECFs retaining their original fiber form and experiencing only a 9.18% reduction in adsorption capacity after 5 cycles. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy were used to study the characterization of QECFs, the preparation mechanism of QECFs, and the adsorption mechanism of DCF by QECFs. Quaternary ammonium groups (R4N+) were well developed in QECFs through the reaction between amino/hydroxyl groups on chitosan and CHTAC, and approximately 0.98 CHTAC molecule with 0.98 R4N+ group were immobilized on each chitosan monomer. Additionally, these R4N+ on QECFs played a crucial role in the removal of DCF.

Fabrication and characterization of an antibacterial chitosan-coated allantoin-loaded NaCMC/SA skin scaffold for wound healing applications

The field of tissue engineering has recently emerged as one of the most promising approaches to address the limitations of conventional tissue replacements for severe injuries. This study introduces a chitosan-coated porous skin scaffold based on sodium carboxymethyl cellulose (NaCMC) and sodium alginate (SA) hydrogels, incorporating allantoin (AL) as an antibacterial agent. The NaCMC/SA hydrogel was cross-linked with epichlorohydrin (ECH) and freeze-dried to obtain a three-dimensional porous structure. The coated and non-coated scaffolds underwent comprehensive evaluation and characterization through various in-vitro analyses, including SEM imaging, swelling, degradation, and mechanical assessments. Furthermore, the scaffolds were studied regarding their allantoin (AL) release profiles, antibacterial properties, cell viability, and cell adhesion. The in-vitro analyses revealed that adding a chitosan (CS) coating and allantoin (AL) to the NaCMC/SA hydrogel significantly improved the scaffolds' antibacterial properties and cell viability. It was observed that the NaCMC:SA ratio and ECH concentration influenced the swelling capacity, biodegradation, drug release profile, and mechanical properties of the scaffolds. Samples with higher NaCMC content exhibited enhanced swelling capacity, more controlled allantoin (AL) release, and improved mechanical strength. Furthermore, the in-vivo results demonstrated that the proposed skin scaffold exhibited satisfactory biocompatibility and supported cell viability during wound healing in Wistar rats, highlighting its potential for clinical applications.

Effect of cross-linking agent concentration on adsorption performance of PVDF ultrafiltration membrane

Small molecule organic pollutants in water endanger both environmental safety and human health. However, because of their small molecular size, they are challenging to remove using conventional polyvinylidene difluoride (PVDF) ultrafiltration membranes for permeate separation. In this study, a regenerable PVDF ultrafiltration membrane with excellent small molecule organic pollutant adsorption capacity was prepared by controlling the epichlorohydrin (EPI) concentration during the cross-linking of hydroxypropyl-cyclodextrin (HP-β-CD). It was found that raising the EPI concentration had no apparent effect on the membrane's composition but produced a dense membrane structure. When the EPI volume percentage was 2%, the cross-linked PVDF ultrafiltration membrane showed superior permeate separation and phenolphthalein adsorption compared to the base membrane (uncross-linked with HP-β-CD). The separation/adsorption experiments under long running time revealed that the ultrafiltration membrane had good stability, and when BSA was present in the feed solution, the adsorption rates of bisphenol A and 2-naphthol with ultrafiltration membranes were 55% (240 min) and 64% (180 min), respectively, and the rejection of BSA was 90%. After 10 adsorption-desorption cycles, the cycle index of the cross-linked PVDF ultrafiltration membrane was 44% for bisphenol A adsorption and 60% for 2-naphthol adsorption.

Cross-linking of Gelatin with Epichlorohydrin in a Sodium-Acetate-Trihydrate/Urea Deep Eutectic Solvent System

To improve the cross-linking efficiency of gelatin molecules, sodium acetate trihydrate/urea deep eutectic solvent with 30% water (SAT/U-DES30W, based on DES weight) was proposed as the solvent of gelatin in this paper. The system could overcome the gelation effect of gelatin at low temperature and expose more active groups of gelatin molecules, resulting in better cross-linking effect. Firstly, the optimal reaction concentration of epichlorohydrin (ECH) was determined by boiling water solubility of cross-linking products, and the cross-linking efficiency of gelatin under two systems was judged together with the Glass transition temperature method. Secondly, the water resistance of the cross-linked product was investigated by swelling capacity and water contact angle. The water absorption rate of GEW and GEDES decreased from 4614% to 1500% and 929% at 12 h, respectively, and the water contact angle also obviously decreased, indicating that the cross-linking efficiency of gelatin under DES system was higher. Finally, the cross-linking mechanism of gelatin and ECH were discussed and it was found the thermal stability of GEDES was significantly improved, which would provide a theoretical basis for gelatin-based materials.

Sifat Mekanik dan Densitas Ikatan Silang Hidrogel berbasis Tapioka Nanopartikel

Tapioca is a natural polymer that is widely used as a raw material for hydrogels. In order to improve the mechanical properties of tapioca-based hydrogels, this research modified tapioca by acid hydrolysis method for 2 hours and 24 hours and by ethanol precipitation method. This modified tapioca was further treated with epichlorohydrin with various concentrations of 0, 5, 10, and 20% to produce a three-dimensional cross-linked structure. The results showed that the increasing of epichlorohydrin concentration led to an increasing in the mechanical properties of the hydrogels consisting of hardness, stress, modulus of elasticity, and cross-linked density. The hydrogel from tapioca hydrolyzed for 24 hours and 20% epichlorohydrin was the sample with the best mechanical properties with a hardness of 19.78 mJ, a stress of 78.65 kPa, a modulus of elasticity of 233.84 mJ, and a cross-linked density of 57.61 × 1024 m-3.

Facile Preparation of Cellulose Bioplastic from Cladophora sp. Algae via Hydrogel Method.

Bioplastic has been widely studied in the past decades as a replacement for non-biodegradable and non-environmentally friendly plastic. One of the promising materials to produce bioplastic is cellulose. However, it is rarely used as the main component for bioplastic production. This study reports a facile process to prepare bioplastic using the pure cellulose content of Cladophora sp. algae via the hydrogel method. The effect of epichlorohydrin (ECH) concentrations as the cross-linking agent was investigated toward the biodegradability, thermal, and mechanical properties of the cellulose bioplastic obtained. The results showed that ECH concentrations affected the properties of the cellulose bioplastic produced due to the number of cross-links formed during the process. The cellulose bioplastic possessed relatively high thermal and mechanical properties. The cellulose bioplastic performed excellent biodegradability, as it was degraded by more than 40% within five days. Thus, the cellulose of Cladophora sp. algae has the potential to be developed as the main component for bioplastic application.

Amine-functionalized bimetallic Co/Zn-zeolitic imidazolate frameworks as an efficient catalyst for the CO2 cycloaddition to epoxides under mild conditions

Amine-functionalized bimetallic zeolitic imidazolate framework-8 (Co/Zn-ZIF-A) with 3-amino-1,2,4-triazole (Atz) was synthesized by a post-synthetic modification and utilized as a heterogeneous catalyst for the synthesis of cyclic carbonates from CO2 and epoxides. Different amine contents in Co/Zn-ZIF-A materials were controlled by adjusting the ligand exchange reaction time of the of 2-mIM with Atz. Co/Zn-ZIF-A-24 h with the highest amine contents (32% of Atz) achieved an excellent result of 99% conversion of epichlorohydrin with high selectivity of > 99% after 24 h without co-catalyst and solvent under mild conditions (80 oC, 1 bar CO2). The enhanced catalytic activity is attributed to the acid-base synergistic effect by the combination of bimetallic systems consisting of Zn and Co as Lewis acid sites and the abundant Lewis bases sites of -NH2, -NH groups from Atz ligand. A kinetic study of the cycloaddition reaction over Co/Zn-ZIF-A-24 h confirmed an approximately first-order dependence on the epichlorohydrin concentration and CO2 pressure with an activation energy of approximately 39.5 kJ mol-1. Co/Zn-ZIF-A-24 h catalyst showed good reusability with no obvious loss in catalytic activity during five recycling runs and its structural stability was also confirmed. A plausible reaction mechanism of Co/Zn-ZIF-A catalyst for CO2-epoxide cycloaddition was proposed.

Cellulose-Based Hydrogels as Smart, Green and Controllable Nitrogenous Fertilizers Releasing Agents

Abstract A smart, green, and controllable-release hydrogel based on cellulose was prepared to avoid the problem of soil fertilizer abuse. A field-emission scanning electron microscope (FE-SEM) demonstrated a wrinkled, rough, lamellar structure with long microtubes. The effect of the cross-linker concentration, epichlorohydrin (ECH), on the physical and mechanical properties in addition to swelling and urea-release kinetics was thoroughly studied. A relatively high swelling ratio, urea entrapment, and proper flexibility were obtained for an ECH concentration of 3.33 %. The swelling kinetics of hydrogel was found to be a second-order process. The maximum swelling value and the initial swelling rate were dependent on cross-linker concentration. The hydrogel exhibited a dehydration shrinkage in saline solution. A significantly high urea release of 6.61 % at 3.33 ECH concentrations was estimated. The urea-release mechanism matches well with the Fickian model. Accordingly, the prepared hydrogel is potential as a smart, green, and controllable-release fertilizer for applications in agriculture and horticulture.

Preparation and Kinetic Studies of Cross-Linked Chitosan Beads Using Dual Crosslinkers of Tripolyphosphate and Epichlorohydrin for Adsorption of Methyl Orange.

Preparation of cross-linked chitosan beads using dual crosslinkers of tripolyphosphate (TPP) and epichlorohydrin (ECH) for the adsorption and kinetic studies of methyl orange (MO) had been carried out. FTIR spectra showed that TPP could act as the protecting agent of the NH2 group of chitosan and ECH reacted with the primary hydroxyl group of chitosan. Various concentrations of TPP, ECH, and immersing time in the TPP solution for bead formation were studied. The effect of pH and kinetics of adsorption were investigated to define the mechanism of adsorption and rate-limiting step. As a result, pH 3, 10% (w/v) TPP, 5% (v/v) ECH, and 12 h immersing time in TPP were selected as the optimum conditions for preparing the beads as indicated by the highest adsorption amount of MO. The cross-linked chitosan beads' adsorption capacity for MO under optimum condition was found to be 79.55 mg/g with the adsorption rate constant (k) of 1.29 × 10−3/min. Furthermore, it was found that a low concentration of ECH could maintain the stability of chitosan in acidic conditions, whereas the concentration of TPP and immersing time controlled pore size and morphology of chitosan beads. The mechanism of adsorption of MO was controlled by the pore and rigidity of cross-linked chitosan beads. Bulk diffusion acted as a rate-limiting step, and a high concentration of MO inhibited diffusion and adsorption itself.

A new approach to prepare Polyethylene Glycol Allyl Glycidyl Ether

The polyethylene glycol allyl glycidyl ether (PGAGE) is an important intermediate for preparing silicone softener that can be synthesized from allyl alcohol polyoxyethylene ether and epichlorohydrin (ECH). The performance parameters including the concentration of ECH, initial boron trifluoride diethyl etherate (BFEE) as well as CaCl2 quality were investigated respectively. The optimum process parameters which can get high capping and low by-product rate are as follows: the ECH concentration is 2.0 M, the initial BFEE concentration is 1.65mM, and the CaCl2 dosage is 1.65g/L. Under these conditions, the maximal yield can be improved to 91.36%, the percent of capping rate is higher than 98.16%, the residual concentration of F-is only 0.63 mg/L.

Determination of 1-chloro-2,3-epoxypropane in order to assess the working environment

1-Chloro-2,3-epoxypropane, known as epichlorohydrin (ECH), is a colorless liquid used in the production of epoxy resins, synthetic glycerine, elastomers, glycidyl ethers, surfactants, polyamide-epichlorohydrin resins and others. Epichlorohydrin may cause cancer. The aim of this study was to develop a new method for determining concentrations of ECH in workplace air in the range of 1/10-2 values of the maximum admissible concentration (MAC). The paper presents a method for the determination of ECH in workplace air using a gas chromatograph coupled with a mass spectrometer (GC-MS). The developed method is based on the adsorption of ECH on an activated charcoal, extraction with acetone, and a chromatographic analysis of the resulting solution. The method developed makes it possible to determine ECH in the concentration range of 0.1-2 mg/m3, i.e., 1/10-2 values of MAC established in Poland. The limit of detection (LOD) is 0.24 μg/m3 and the limit of quantification (LOQ) is 0.71 μg/m3. The method is characterized by good precision and accuracy; it meets the requirements of the European standard PN-EN 482, and can be used by occupational hygiene laboratories to measure concentrations of ECH in workplace air, with a view to assessing workers' exposure to this substance. Med Pr. 2020;71(6):715-23.

CO2 cycloaddition to epichlorohydrin over an aluminum fumarate metal-organic framework synthesized by a sonochemical route

Aluminum fumarate was tested as a catalyst for CO 2 cycloaddition to epichlorohydrin under solvent-free reaction conditions. This material was synthesized hydrothermally via a sonochemical route (Al fumarate-(S)), which exhibited a higher catalytic activity than Al fumarate synthesized by a conventional method owing to the higher number of Lewis acid sites formed in Al fumarate-(S). The CO 2 uptake of Al fumarate-(S) was high: approximately 269 mg g −1 at 25 °C and 10 bar. High conversion (96%) of epichlorohydrin with excellent selectivity (97%) to cyclic carbonate was obtained at 50 °C and 10 bar CO 2 after 6 h of reaction. The kinetic analysis of the reaction confirmed an approximately 1st order dependence on the epichlorohydrin concentration and CO 2 pressure with an activation energy of approximately 39 kJ mol −1 . The recovered Al fumarate-(S) catalyst, however, showed a steady decline in catalytic activity during the recycling runs, as reported for other metal-organic framework catalysts. The deactivation was monitored by N 2 adsorption-desorption isotherms and spectroscopic analyses. • The aluminum fumarate metal-organic framework was synthesized via a sonochemical route. • It showed higher amounts of Lewis acid sites and more active for CO 2 cycloaddition than the one conventionally prepared. • A reaction mechanism for CO 2 cycloaddition to epichlorohydrin was proposed.

Preparation, Optimization, and Evaluation of Epichlorohydrin Cross-Linked Enset (Ensete ventricosum (Welw.) Cheeseman) Starch as Drug Release Sustaining Excipient in Microsphere Formulation.

Ensete ventricosum (Welw.) cheeseman which belongs to the family of Musaceae is one of the main sources of starch in Ethiopia. This study aimed at evaluating epichlorohydrin cross-linked enset starch as a drug release sustaining excipient in microsphere formulations of theophylline. Extracted enset starch was cross-linked using epichlorohydrin as a cross-linking agent. The effect of cross-linker concentration, cross-linking duration, and cross-linking temperature on the degree of cross-linking and release rate of microspheres prepared by emulsion solvent evaporation method was investigated using the two-level full factorial design. Accordingly, the concentration of epichlorohydrin and duration of cross-linking were the most significant factors affecting both the degree of cross-linking and drug release rate. Thus, the effects of these two factors were further studied and optimized using the central composite design. As per the numerical method of central composite design, the optimal points were obtained at epichlorohydrin concentration of 13.70% and cross-linking time of 3.82 h. Under these optimal conditions, the model predicts the degree of cross-linking of 74.70% and drug release rate of 28.00 h1/2. The validity of these optimal points was confirmed experimentally. The microspheres of the optimum formulation also exhibited minimum burst release with sustained release for 12 h. Besides, the optimized formulation followed the Higuchi square root kinetic model with non-Fickian diffusion release mechanism. The finding of this study suggested that cross-linked enset starch can be used as an alternative drug-release-sustaining pharmaceutical excipient in microsphere formulation.

Evaluation of Crosslinking Effect on Thermo-mechanical, Acoustic Insulation and Water Absorption Performance of Biomass-Derived Cellulose Cryogels

Cellulose cryogels crosslinked with epichlorohydrin (ECH) were successfully developed from kenaf core biomass via green urea/alkaline solvent system. The effect of ECH concentration (from 3 to 9 wt%) on the pore structure, density, morphology, thermal stability, mechanical properties, water absorption performance and acoustic insulation of cellulose cryogels were studied. It was found that the introduction of ECH affected the porosity and pore volume as well as density and water absorption of cryogels. The increase percentage of ECH has delayed the thermal decomposition of the cellulose cryogels thereby improving their thermal stability. Moreover, the compress stress and the sound absorption coefficient of the cellulose cryogels were enhanced significantly by about 50% and 27%, respectively. This work provides a facile approach to produce cost-effective biomass-derived cellulose cryogels with improved mechanical and thermal stability properties as well as acoustic insulation for preliminary studies of industrial applications.

Physicochemical, functional and structural characterization of Mexican Oxalis tuberosa starch modified by cross-linking

Chemical modification of the native starch of Mexican Oxalis tuberosa was studied by cross-linking it with different concentrations of epichlorohydrin (0.5–2%). The results showed an extraction yield of 65.1 ± 0.20% (dry basis) for native starch, which can be considered as a potential unconventional source for starch extraction. The amylose contents of native and modified starch decreased from 24.66 to 13.57%, respectively. X-ray diffraction analysis showed an increase in the crystalline part in modified starch. The chemical modification changed the functional properties of starch. The clarity of the paste determined by spectrophotometer at 650 nm showed an inversely proportional relationship with the epichlorohydrin concentration. The lipid absorption index showed an increase up to 210% (using 2% epichlorohydrin) compared to that of native starch. The structure was analyzed by SEM and showed granules before and after the modification an ellipsoid morphology while the polarized light microscopy analysis showed birefringence patterns. The average diameter of the granules evaluated using a particle size analyzer (CILAS) ranged between 31.46 μm and 35.32 μm for modified starch and was 30.36 μm for the native starch, both higher than that of the corn-starch granules (16.10 μm). This makes the Mexican O. tuberosa an option for starch extraction and for application in the food industry.

Epichlorohydrin‐Induced DNA‐Protein Cross‐Links in Human Leukemia Cells

Over 1.5 million tons of epichlorohydrin (ECH) are used annually in the manufacturing of epoxy resins and polymers. A probable human carcinogen, ECH shares structural homology to nitrogen mustards, the oldest class of anti‐tumor drugs. Such bifunctional alkylating agents can react with DNA and proteins, leading to genotoxic effects. Previous work in our lab has shown that treating human leukemia (HL‐60) cells with toxic doses of ECH leads to the formation of cross‐links and triggers apoptosis. In these studies, cross‐linking was quantified via single cell gel electrophoresis (the comet assay), which does not distinguish between DNA‐DNA cross‐links and DNA‐protein cross‐links (DPCs). The goal of this work is to further characterize ECH‐induced DPCs. Nuclear proteins that bind to biotinylated DNA after treating HL‐60 cells with ECH under different conditions are captured via streptavidin beads. Cross‐linked proteins are then characterized through gel electrophoresis. Preliminary data suggest that ECH does induce DPC formation, with greater cross‐linking efficiency at higher concentrations of ECH. Our findings could have significance for understanding the occupational risks of ECH exposure among industrial workers.Support or Funding InformationSupported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM0103423.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Overexpression of epoxide hydrolase in Rhodococcus ruber with high robustness for the synthesis of chiral epichlorohydrin

Abstract Epoxide hydrolases (EHs) are attractive enzymes for producing enantiopure epoxides and diols, but do not display enough stability when lysates or Escherichia coli whole cells are used as biocatalysts. In this work, an organic-solvent tolerant strain Rhodococcus ruber THdAdN was utilized to overexpress an epoxide hydrolase from Agrobacterium radiobacter (ArEH), using E. coli BL21(DE3) as a control. The proportion of ArEH in all soluble proteins of R. ruber THdAdN(ArEH) reached 30.3%, which was comparable to that of E. coli BL21(DE3)(ArEH). Due to a higher cell density in flask cultivation, the maximum ArEH activity of R. ruber THdAdN(ArEH) toward epichlorohydrin (ECH) reached 5.4 U/mL, approximately 5-fold higher than that of E. coli BL21(DE3)(ArEH). More importantly, compared with E. coli BL21(DE3)(ArEH), ArEH in R. ruber THdAdN(ArEH) showed a 10-fold enhanced thermostability, better tolerance against alkali pH, and reduced substrate and product inhibition, which significantly improved its performance in the resolution of high concentration ECH. By substrate feeding, 98.5% ee (R)-ECH was obtained with a 35.5% yield from 512 mM racemic ECH hydrolyzed by R. ruber THdAdN(ArEH). Compared with using free enzyme as biocatalysts, utilization of the R. ruber cells harboring ArEH improved the final (R)-ECH concentration by 46%.

Chemically crosslinked hydrogel and its driving force towards superabsorbent behaviour

Dissolved oil palm empty fruit bunch (EFB) cellulose in NaOH/urea solvent was mixed with sodium carboxymethylcellulose (NaCMC) to form a green regenerated superabsorbent hydrogel. The effect of concentration of epichlorohydrin (ECH) as the crosslinker on the formation, physical, and chemical properties of hydrogel was studied. Rapid formation and higher gel content of hydrogel were observed at 10% concentration of ECH. The superabsorbent hydrogel was successfully fabricated in this study with the swelling ability >100,000%. Hydrogel with higher concentration of ECH showed opposite trend by having higher superabsorbent property than that of lower concentration. The covalent bond of COC was observed with Attenuated total reflectance fourier transform infrared (ATR-FT-IR) spectroscopy to confirm the occurrence of crosslinking. The physical and chemical properties of hydrogel were affected by swelling phenomenon. Hydrogel with higher degree of swelling exhibited lower moisture retention and higher transparency. Moreover, the weight of the superabsorbent hydrogel increased with the decrement of pH value of external media (distilled water). This study provided substantial information on the effect of different percentage of ECH as crosslinker on hydrogel basic properties. Furthermore, this study affords correlation of many essential driving forces that affected hydrogel superabsorbent property.

Electrochemically mediated reduction of epichlorohydrin pollutant by Ni(I)(hexamethylcyclam) in aqueous media

Epichlorohydrin (ECH) is a volatile organic compound and toxic to human health. Here we investigated clean mediated electrocatalytic dechlorination of ECH in aqueous solutions using electrogenerated [Nickel(I)(hexamethylcyclam)]+ ([Ni(I)(hmc)]+) at glassy carbon cathode. Ni(II)/Ni(I) redox behavior of [Ni(II)(hmc)]2+, examined first by cyclic voltammetry in ECH free-aqueous solutions of various anions (Cl−, Br−, ClO4−, SO42−, phosphate, NO3−), showed only Cl− could provide most stable and reactive low-valent nickel species with highest versatility toward activation of ECH dechlorination. Cyclic voltammetry experiments over a range of scan rates and ECH concentrations elucidated rate limiting mechanism for Ni(I) catalyzed ECH dechlorination, and estimated catalytic reaction rate constant (kcat). ECH concentration-dependent kcat and icat results revealed ECH dechlorination by Ni(I) followed Michaelis-Menten type inner-sphere electron transfer kinetics at low ECH concentrations (< 20mM), but outer-sphere mechanism at higher concentrations. Interestingly, GC/MS showed complete destruction of ECH and production of three non-chloro products within 3-h bulk electrolysis. A possible mechanism was proposed for the overall Ni(I)(hmc)-catalyzed ECH dechlorination. Fast mediation kinetics, total removal of ECH, non-chloro organics as the only dechlorination products, and highly stable [Ni(I)(hmc)]+ mediator indicate electrocatalytic mediation using [Ni(I)(hmc)]+ in aqueous NaCl solution may be feasible for dechlorination of other organic chloro compounds.

A novel method for immobilization of proteins via entrapment of magnetic nanoparticles through epoxy cross-linking

A method for immobilization of functional proteins by chemical cross-linking of the protein of interest and uncoated iron oxide nanoparticles in the presence of Epichlorohydrin is described. As a result of the cross-linking, the proteins form a matrix in which the particles get entrapped. The optimum concentration of Epichlorohydrin that facilitates immobilization of protein without affecting the functional properties of the protein was determined. This method was used to immobilize several functional proteins and the development and functional activity of Protein A-magnetic nanoparticles (MNPs) is described here in detail. The Protein A-MNPs possess high binding capacity due to the increased surface area of uncoated nanoparticles and robust magnetic separation due to the absence of polymeric coating materials. Protein A-MNPs were successfully used for purification of antibodies and also for immunoprecipitation. We also immobilized enzymes such as horse radish peroxidase and esterase and found that by providing the optimum incubation time, temperature and protein to nanoparticle ratio, we can retain the activity and improve the stability of the enzyme. This study is the first demonstration that Epichlorohydrin can be used to entrap nanoparticles in a cross-linked matrix of protein without impairing the activity of immobilized protein.