Electron Mediator Technologies

Electron mediators are critical chemical components in modern diabetic test strips that shuttle electrons from the glucose enzyme to the sensor electrode, replacing oxygen which was used in first-generation sensors. The introduction of artificial mediators, starting with Ferrocene in the 1980s (ExacTech), allowed for the development of electrochemical biosensors that are independent of blood oxygen levels.

Key mediator technologies include Potassium Ferricyanide (common, cheap, but prone to interference), Ferrocene (historically significant), and Osmium/Ruthenium complexes (used in 'wired' enzyme technology like Abbott FreeStyle). The latter allows for operation at very low electrical potentials, significantly reducing interference from common blood components like acetaminophen and Vitamin C. Current innovation focuses on stabilizing these mediators and pairing them with oxygen-insensitive enzymes (GDH-FAD) to maximize accuracy.