Chapter 17, Problem 17.26P

(a)

Interpretation Introduction

Interpretation:

The process involved in monitoring glucose level in amperometric glucose monitor has to be explained.

(b)

Interpretation Introduction

Interpretation:

The benefits of mediator in glucose monitor has to be explained.

(c)

Interpretation Introduction

Interpretation:

The process involved in monitoring glucose level in coulometric glucose monitor has to be explained.

(d)

Interpretation Introduction

Interpretation:

The signal dependence on amperometric measurement has to be explained.

(e)

Interpretation Introduction

Interpretation:

The current required to monitor glucose level with given concentration has to be calculated.

Concept introduction:

Amperometric glucose monitor contains a test strip which is made of two carbon electrodes and a reference electrode (silver-silver chloride).  A mediator and glucose oxidase is coated on carbon electrode.  While placing a drop of blood on strip, glucose in blood get oxidized to gluconolactone and mediator get reduced.  On applying potential of $\text{0}\text{.2V}$ on carbon electrode, re-oxidation happens in reduced mediator at the carbon electrode.  The speed of oxidation of the mediator is directly proportional to cureent between both electrodes.  The strength of glucose and additional species in blood is proportional to rate of oxidation of mediator.  Indicator electrode two has only mediator without glucose oxidase.  Measurement of current between reference electrode and indicator electrode two is relative to strength of species other than glucose.  The strength of glucose is proportional to change in two currents.