Immobilized enzyme

About: Immobilized enzyme is a research topic. Over the lifetime, 15282 publications have been published within this topic receiving 401860 citations.

Gold nanoparticles-mesoporous silica composite used as an enzyme immobilization matrix for amperometric glucose biosensor construction

Abstract: Gold nanoparticles-mesoporous silica composite (GNPs-MPS) is developed as a novel enzyme immobilization matrix for biosensor construction The mesoporous silica SBA-15 is chosen and the GNPs-SBA-15 is formed from AuCl4− adsorbed H2N-SBA-15 by NaBH4 reduction The synthesis process of the composite is monitored by UV–vis spectroscopy and the product is characterized by transmission electron microscopy (TEM) measurement An amperometric glucose biosensor is built by immobilizing IO4−-oxidized-glucose oxidase (IO4−-oxidized-GOD) on GNPs-MPS modified Au electrode using 2-aminoethanethiol as a cross-linker Cyclic voltammetry (CV) and amperometry are employed to investigate the catalytic behavior of the biosensor to the oxidation of glucose As a result, the biosensor exhibits an excellent bioelectrocatalytic response to glucose with a fast response time less than 7 s, a broad linear range of 002–14 mM, high sensitivity of 61 μA mM−1 cm−2, as well as good long-term stability and reproducibility These performances could be ascribed to the GNPs-MPS's features, such as excellent conductivity, large surface area and good biocompatibility

One-Pot Preparation of Polymer–Enzyme–Metallic Nanoparticle Composite Films for High-Performance Biosensing of Glucose and Galactose

Abstract: New polymer–enzyme–metallic nanoparticle composite films with a high-load and a high-activity of immobilized enzymes and obvious electrocatalysis/nano-enhancement effects for biosensing of glucose and galactose are designed and prepared by a one-pot chemical pre-synthesis/electropolymerization (CPSE) protocol. Dopamine (DA) as a reductant and a monomer, glucose oxidase (GOx) or galactose oxidase (GaOx) as the enzyme, and HAuCl4 or H2PtCl6 as an oxidant to trigger DA polymerization and the source of metallic nanoparticles, are mixed to yield polymeric bionanocomposites (PBNCs), which are then anchored on the electrode by electropolymerization of the remaining DA monomer. The prepared PBNC material has good biocompatibility, a highly uniform dispersion of the nanoparticles with a narrow size distribution, and high load/activity of the immobilized enzymes, as verified by transmission/scanning electron microscopy and electrochemical quartz crystal microbalance. The thus-prepared enzyme electrodes show a largely improved amperometric biosensing performance, e.g., a very high detection sensitivity (99 or 129 µA cm−2 mM−1 for glucose for Pt PBNCs on bare or platinized Au), a sub-micromolar limit of detection for glucose, and an excellent durability, in comparison with those based on conventional procedures. Also, the PBNC-based enzyme electrodes work well in the second-generation biosensing mode. The proposed one-pot CPSE protocol may be extended to the preparation of many other functionalized PBNCs for wide applications.

Immobilization of beta-glucosidase on Eupergit C for lignocellulose hydrolysis

Abstract: beta-Glucosidase is frequently used to supplement cellulase preparations for hydrolysis of cellulosic and lignocellulosic substrates in order to accelerate the conversion of cellobiose to glucose. Typically, commercial cellulase preparations are deficient in this enzyme and accumulation of cellobiose leads to product inhibition. This study evaluates the potential for recycling beta-glucosidase by immobilization on a methacrylamide polymer carrier, Eupergit C. The immobilized beta-glucosidase had improved stability at 65 degrees C, relative to the free enzyme, while the profile of activity versus pH was unchanged. Immobilization resulted in an increase in the apparent Km from 1.1 to 11 mM: and an increase in Vmax from 296 to 2430 micromol mg(-1) min(-1). The effect of immobilized beta-glucosidase on the hydrolysis of cellulosic and lignocellulosic substrates was comparable to that of the free enzyme when used at the same level of protein. Operational stability of the immobilized beta-glucosidase was demonstrated during six rounds of lignocellulose hydrolysis.

Direct binding of protein to magnetic particles

Abstract: A new method of binding bovine serum albumin on to freshly precipitated magnetic particles is reported. The binding was confirmed by electron micrograph studies, magnetic measurements and FTIR spectroscopy. Under optimum conditions more than 90% of the protein was bound to the magnetic particles. When alkaline phosphatase was immo-bilised using this method, it retained 75% enzyme activity. The method may prove to be applicable to radio-immuno assays (binding of antibodies to magnetic particles), cell and enzyme immobilisation and in affinity chromatography