In quantifying glucose using an amperometric glucose electrode system, which of the following is not a component of the system?

In quantifying glucose using an amperometric glucose electrode system, which of the following is not a component of the system?

• A. Product oxidation produces a current
• B. Hydrogen peroxide formed
• C. Hexokinase reacts with glucose
• D. Platinum electrode

Answer: (C)

In amperometric glucose sensing, the signal comes from the electrochemical oxidation (or reduction) of a product formed during glucose oxidation at an enzyme electrode. Glucose is oxidized by glucose oxidase, generating hydrogen peroxide, and the electrode (often platinum) detects the oxidation of that hydrogen peroxide, producing a current proportional to the glucose level. The platinum electrode is the site where this electron transfer occurs, and the hydrogen peroxide produced is the species whose oxidation generates the measurable current. Hexokinase, by contrast, is a glycolytic enzyme that phosphorylates glucose in metabolic pathways and is not part of the electrochemical detection pathway used in amperometric glucose sensors. Therefore, it does not belong in the amperometric glucose electrode system.

In amperometric glucose sensing, the signal comes from the electrochemical oxidation (or reduction) of a product formed during glucose oxidation at an enzyme electrode. Glucose is oxidized by glucose oxidase, generating hydrogen peroxide, and the electrode (often platinum) detects the oxidation of that hydrogen peroxide, producing a current proportional to the glucose level. The platinum electrode is the site where this electron transfer occurs, and the hydrogen peroxide produced is the species whose oxidation generates the measurable current.

Hexokinase, by contrast, is a glycolytic enzyme that phosphorylates glucose in metabolic pathways and is not part of the electrochemical detection pathway used in amperometric glucose sensors. Therefore, it does not belong in the amperometric glucose electrode system.