Enzyme sensors based on the measurement of pH consist basically of a pH-sensitive electrode to which an enzyme-loaded membrane is attached. The conversion of substrate in the immobilized enzyme membrane results in a local change in pH which can then be measured. The pH-sensitive electrode used is usually a glass membrane electrode or an ISFET. In 1980, Caras and Janata [l] described the first I...

This laboratory seeks to quantitatively determine glucose concentration in common beverages. The method employed is enzyme catalyzed oxidation of glucose, quantified by chronoamperometry. With an inexpensive patterned electrode and low cost glucose oxidase enzyme, an electrochemical sensor is constructed to selectively measure glucose in complicated beverages which can present as analytically c...

Enzyme sensor for organophosphorus insecticides organophosphorus hydrolase in a polymer membrane on a pH sensor is used to catalyse the hydrolysis of compounds with phoshate ester functionality. The detected [H+] change is proportional to the concentration of the phosphate ester insecticide. This is a good example of the use of an enzyme to give selectivity to a specific class of compounds. Unf...