Amperometric determination of enzymatic activity by multienzyme biosensors

A Clark type, amperometric, multienzyme electrode, employing glucose oxidase and mutarotase, was used to determine the enzymatic activity of a model enzyme, invertase, in soluble and immobilized forms. A calibration curve with linear range up to 70 IU of invertase activity corresponding to the 6.0 nA/s of electrode response was sketched. It is shown that, multienzyme electrodes can be utilized as a very rapid, reliable and sensitive tool for the determination of enzymatic activity either in a free or immobilized form.