Enzyme electrodes lactose

Several other sensors are available that are based on the amperometric measurement of hydrogen peroxide produced by enzymatic reactions. The analytes measured include sucrose, lactose, ethanol, and L-lactate. A different enzyme is, of course, required for each species. In some cases, enzyme electrodes can be based on measuring oxygen or on measuring pH. 

Between 15 and 20 analyzers based on enzyme electrodes are on the market worldwide. They are one-parameter instruments for the measurement of glucose, galactose, uric add, choline, ethanol, lysine, lactate, pesti-ddes, sucrose, lactose, and the activity of a-amylase (Table 23). They provide for a negligible enzyme consumption of less than 1 pg per sample. 

Albery, J. W., Kaha, Y. N., and Magner, E. 1992. Amperometric enzyme electrodes. Part VI. Enzyme electrodes for sucrose and lactose. J. Electroanal. Chem. 325 83-93. 

Construction principles and the mechanism for biosensors derived from enzymes. Combined enzymatic and electrochemical reactions proceeding on electrodes from various materials in electrolyte solutions promote development of many biosensor types for detection of glucose, amino acids, lactose, urea, pyruvate and other metabolites. Biosensors are successfully applied to environmental contamination control, medical diagnostics and the food industry. 

Initial and most detailed studies were made with CDH from Phanerochaete chrysosporium. The enzyme was immobilized by simple adsorption onto graphite electrodes and in the presence of cellobiose or lactose but without external mediator, a response current to cellobiose was registered providing indirect proof of DET [109,225]. 

Hydrolysis and other Reactions and Features.—A. novel method for following the add catafysed hydrolysis of sucrose and lactose involves measurement of the rate of reaction of periodate with quenched aliquot portions of the solutions using a periodate>sensitive electrode. In this way sucrose could be determined in the presence of other carbohydrates in the range 0.01-0.1 M, and the method was applied to food products. The glycosidic hydrolysis of fluorenone ketal (107), which serves as a nucleoside glycosylase enzyme model, has been shown to be intramolecularly catalysed by comparison with analogous compounds. ... 

---