Enzymes immobilising entrapment method

However, the main goal was to study the behavior and performance of a novel bioartificial material (obtained with an innovative method involving prefreezing and inversion steps) as a suitable matrix for the entrapment of proteins or enzymes in a stable manner. The tests performed (determination of enzyme activity, determination of and V ax kinetic parameters, repeatability test) confirmed both that the enzyme immobilised in the bioartificial polymeric matrix maintained its catalytic activity unchanged and that the catalytic reaction rate was comparable with that of the free a-amylase reaction (used as control). 

Figure 10.5 Different methods of enzyme immobilisation on conducting polymers (a) physical adsorption (b) crosslinking by bifunctional reagents (c) covalent bonding to the matrix (d) entrapment within the polymer matrix (e) immobilisation in a conducting polymer polyvinyl carbazole (PVCZ)/stearic acid (StA) monolayer using...

It is well known that pine enzymes change then behaviour and stability when they are immobilised. In the past two decades the immobilisation of microorganisms, cells and parts of cells has gradually been introduced into microbiology and biotechnology. The cell immobilisation techniques are modifications of the techniques developed for enzymes. However, the larger size of microbes has influenced the techniques. As for immobilised enzymes, two broad types of method have been used to immobilise microorganisms attachment to a support and entrapment. 

A wide variety of methods exist for the immobilisation of enzymes on a sensor surface. Screen-printed carbon electrodes are often the favourite base for these sensors due to their inexpensiveness and ease of mass production. Methods used for the construction of AChE-containing electrodes include simple adsorption from solution [22], entrapment within a photo-crosslinkable polymer [20,23], adsorption from solution onto microporous carbon and incorporation into a hydroxyethyl cellulose membrane [24], binding to a carbon electrode via Concanavalin A affinity [25,26] and entrapment within conducting electrodeposited polymers [27]. 

Immobilisation of biomolecules on the surface of an effective matrix with maximum retention of their biological recognition properties is a crucial problem for the commercial development of a biosensor. Different methods of immobilisation have been used. One such method is electrochemical entrapment. Several conducting polymers can be deposited electrochemically and, in the process, a biological molecule can be entrapped. This process is also useful in the fabrication of microsensors in preparation of a multilayered structure with one or more enzymes/biomolecules layered within a multilayered copolymer for analysis of multiple analytes [133-135]. A number of reports have appeared on immobilisation of biomolecules using electrochemical entrapment [130, 131, 136-143]. 

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