Lawrence Deo, and Wang (Anal. Chem., 2004, 76, 3735) have described an electrochemical biosensor for determining glucose based on a carbon paste electrode.
(a) What electrochemical technique is used with the enzyme electrodes described?
(b) What are the advantages of incorporating an enzyme in a carbon paste electrode matrix?
(c) What is a mediator and how is it used with these biosensors?
(d) What is the advantage of using a mediating paste liquid instead of a conventional carbon paste electrode?
(e) Give the enzyme and mediator reactions.
(f) What was cyclic voltammetry used for in the Lawrence, Deo, and Wang study?
(g) What are the approximate response times for these electrodes?
(h) Which of the new mediators gave the highest sensitivity? Which gave the wider linear dynamic range?
(i) Discuss in detail how the current measured with these biosensors is related to the glucose reaction rate. How was the Michaelis constant Km determined?