Enzymes Immobilization on Clays

The swelling ability of these naturally occurring materials provides unusual properties and appreciable surface area for adsorption of organic molecules [15, 30], as was mentioned in Section 2.2.1.1. For the last 25 years different research groups have studied the immobilization of different biomolecules, including enzymes, proteins, nucleic acids [31] as well as cells [32-35] in layered materials. More specifically, various enzymes have been immobilized on clays, including hydrolases and oxidoreductases (see Table 2.1). 

Recently, the functionalization of clays has been used to increase the immobilization efficiency of enzymes and other biomolecules [63]. The clay surface may be modified through reactions with various functional groups, such as thiol, 

Glucose oxidase Modified Y zeolite matrix Amperometric glucose biosensor [36] 

Glucose oxidase Kaolinite (KGa-1), illite, bentonite, nontronite(SWa-l, ferruginous smectite), montmorillonite (SWy-1), and vermiculite (VTx-1), Amperometric glucose biosensor [37] 

Glucose oxidase Laponite Amperometric glucose biosensor [38] 

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Enzymes immobilized on clays have been applied in various industrial processes including food technology [51], peptide synthesis [42, 43], pharmaceuticals [66], biosensors [39, 41, 46, 48], construction of modified electrodes [40, 52] as well as in bioremediation processes [50]. Table 2.1 presents some examples concerning the use of immobilized enzymes on clays. 

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