measuring blood glucose concentration

• Biosensor

  A device used by people with diabetes to show their current blood glucose concentration
• Biosensor components

  • Glucose oxidase immobilized on a recognition layer
  • Partially permeable membrane
• Partially permeable membrane

  Allows only small molecules from the blood to reach the immobilized enzymes
• Measuring blood glucose concentration

  1. Test blood sample

  2. Glucose oxidase catalyzes reaction

  3. Glucose oxidized to gluconic acid and hydrogen peroxide

  4. Hydrogen peroxide oxidized at electrode

  5. Electron flow detected
• Electron flow

  Proportional to glucose concentration of the blood sample
• Biosensor function

  Amplifies the current and produces a digital reading for blood glucose concentration
• This process is complete within a matter of seconds
• Urine test strip will only produce a positive result for glucose
• Other sugars

  • Fructose
  • Sucrose
  • Lactose
• Other sugars such as fructose, sucrose, lactose will give a negative result
• Specificity of glucose oxidase enzyme

  Responsible for urine test strip results
• glucose biosensor diagram