Stabilization via Encapsulation

Alternatively, methods of enzyme encapsulation can provide a means to stabilize proteins in a protective environment by either trapping the protein, wiring the protein to a polymer backbone, or specifically depositing enzymes within micellar pockets [29-32]. Enzymes immobilized within the pores of hydrophobically modified micellar polymers such as Nafion and chitosan, for example, have been shown to effectively stabilize enzymes at electrode surfaces and promote operation lifetimes of more than 2 years [29]. 

Redox catalysts can be stabilized by encapsulation during silica sol-gel formation [33-35], in which the conductivity of the silica matrix is achieved by coimmobilization of a conductive material, such as carbon nanotubes (CNTs). The cationic protein lysozyme catalyzes and templates the formation of silica directly onto a conductive carbon paper electrode. Inclusion of CNT and glucose oxidase (GOx) into the reaction mixture results in a catalytic composite that becomes encapsulated as the silica forms [36]. 

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