ABSTRACT
The most commercially successful biosensors are amperometric enzyme glucose biosensors for monitoring diabetes, which account for approximately 85% of the current world market. Glucose oxidase (GOD) is the standard enzyme for glucose biosensors, and it has a higher selectivity for glucose. GOD is a stable enzyme that can withstand extremes of pH, ionic strength, and temperature compared with many other enzymes, which allows less stringent conditions during the manufacturing process and relatively relaxed storage norms for use. It is also cost-effective and commercially available. Thus, GOD is widely used for the construction of glucose biosensors. The chapter describes the biosensor construction for a typical metabolic compound, Adenosine Triphosphate (ATP), which is based on sequential enzymatic reactions and the detection of the substrate consumption and enzymatic product. Biosensors for enzyme activities are generally constructed based on the detection of a decrease in substrates or an increase in products from the enzymatic reaction.
