Amperometric Biosensing: wiring of enzymes to diamond electrodes with redox polymer brushes

Enzyme electrodes constitute a common type of biosensor and are often employed to detect biochemical analytes under physiological conditions. In this example, a boron-doped nanocrystalline diamond electrode is biofunctionalized with a polymer brush containing glucose oxidase enzymes and ferrocene-based electron mediators. The enzymes selectively catalyze the oxidation of glucose to gluconolactone while the electrons coming from this so-called recognition reaction can transfer via the mediators to the diamond electrode. In this amperometric sensing method, the generated current is proportional to the amount of oxidized glucose.