Glucose electrode third generation

Third-Generation Glucose Electrodes Potentiometric Urea Elearode... 

Fig. 5. Schematic illustration of the three generations of glucose electrodes (A) first generation, (B) second generation, (C) third generation. E, enzyme.

A vast amount of literature exists on enzyme-modified metal nanopartides. Crumbliss and co-workers pioneered the use of metal nanopartides for enzymatic sensors for various analytes such as H2O2, glucose, xanthine and hypoxanthine [156-158]. GCE or Pt electrodes are modified with enzyme-capped Au colloids, either by simple evaporation or electrodeposition. The nanopartides act as mediators, transferring electrons between the redox-active site on the immobilized biomolecule and the electrode and thus eliminating the need for external mediators. These sensors are classified as third generation biosensors . 

Khan, G., Ohwa, M., and Wernet, W., Design of a stable charge transfer complex electrode for a third-generation amperometric glucose sensor. Anal. Chem., 68, 2939-2945 (1996). 

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