The mechanism of glucose meter

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The mechanism of glucose meter

• 2006/5/8

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Teststrip Architecture
Accu-Chek Active
Accu-Chek Go
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Accu-Chek Active Test Strip before Blood
Application
Application Field
Reaction Layer 1
Reaction Layer 2
Yellow Foil
Light Beam
Detection
Application Field
Test Strip after Blood Application
Erythrocytes
Reaction Layer 1
Reaction Layer 2
Yellow Foil
Light Beam
Detection
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Accu-Chek Go Test Strip before Blood Application
Blood Flow from the Capillary
Reaction Layer 1
Reaction Layer 2
Yellow Foil
Light Beam
Detection
Erythrocytes
Test Strip after Blood Application
Reaction Layer 1
Reaction Layer 2
Yellow Foil
Light Beam
Detection
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• Accu-Chek Active / Accu-Chek Go
• from Blood Application to the Glucose Result (1)
• The reaction zone consists of two very thin
  layers which are not visible for the eye.
• Reaction layer 1 contains Titanium Dioxide
  (reflects the light beam
• nearly completely)
• Reaction layer 2 contains the chemistry (in this
  layer the colour is formed)
• After blood application
• blood flows through the capillary of the strip
  (Accu-Chek Go only), then arrives above reaction
  layer 1
• erythrocytes are kept above the reaction layer 1
• cannot interfere with the reaction
• only plasma is involved in the test
• in reaction layer 2 the blue colour develops

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Accu-Chek Active / Accu-Chek Go from Blood
Application to the Glucose Result (2)
After the reaction, the back of the strip is
green (combination of the blue colour of the
indicator and the yellow film) The blue colour
absorbs the light, only a part of the light is
reflected The intensity of the reflected light
depends on the deepness of the blue colour the
deeper the colour the fainter the reflected light
which is measured by the meter
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Teststrip Architecture Accu-Chek Advantage
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Accu-Chek Sensor from Blood Application to
Glucose Result The reaction zone consists of
one thin layer which contains the complete
chemistry of the test There exists no need to
remove erythrocytes because colour does not
influence the glucose result ) Blood
application is detected by the meter as a current
surge

) Hct-dependency
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Reaction Principle Accu-Chek Advantage

The PQQ-dependent enzyme (glucose-dye-oxidoreducta
se) oxidizes ß-D glucose to D-5-gluconolactone,
while at the same time the enzyme-bound co-enzyme
PQQ ( pyrroloquinolone quinone) is reduced to
PQQH2
The enzyme transfers the reduction equivalents of
PQQH2 to the oxidized form of the mediator
hexacyanoferrate (III), which results in the
reduced form of the mediator, hexacyanoferrate
(II)
The meter then applies a voltage between the two
Palladium electrodes of the test strip. The
reduced mediator (hexacyanoferrate II) is
reoxidized into hexa-cyanoferrate III which
releases electrons. The electron flow that is
released is proportional to the glucose
concentration of the sample and is measured by
the Accu-Chek Sensor/ Accu-Chek Advantage meter
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Reaction Principle Accu-Chek Active / Accu-Chek
Go vs. Accu-Chek Sensor
Glucono-lactone
Glucono-lactone
Glucose
Glucose
Enzyme (PQQH2)red
Enzyme (PQQH2)red
Enzyme (PQQ)OX
Enzyme (PQQ)OX
Mediatorred
Mediatorred
Mediatorox
Mediatorox
Palladium Electrode
Indicatorred (blue)
Indicatorox (yellow)