Enzymes immobilized on an electrode

Enzyme electrodes — An enzyme electrode consists of an enzyme immobilized on an electrode, the function of the enzyme electrode being essentially connected with the catalytic activity of the immobilized enzyme. The electrochemical response of an enzyme electrode can be based either on the enzymatic generation of electroactive species or on the electrochemical communication of the enzyme with the electrode. 

On the basis of all the available data, we can assert that enzymes immobilized on an electrode which catalyze electrochemical transformations preserve their molecular integrity and principal bioelectrocatalytic characteristics. The proof of this is found in the following three groups of experimental facts. 

Although the model provides a mechanism to measure the total activity of enzyme immobilized on an electrode, it also allows estimation of the combined mass transfer parameter (A/nad+) for the diffusing substrate (in this case, NAD" ). This value, however, is limited somewhat by the fact that the term is cumulative for several variables that may individually contribute to overall electrode mass transfer combined contributions of the molecular diffusion coefficient, effective surface area, diffusion length, pore structure, and mass transfer through the film. Unfortunately, this approach will remain limited unless additional modeling is incorporated that can specifically differentiate these parameters. If more parameters are to be added to the... 

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