Electrochemical Biosensors

November 7, 2014 13:14 PSP Book - 9in x 6in 08-Serge-Cosnier-c08

238 Electroenzymatic Labeling for Immunosensors and DNA Sensors

enzyme, which catalyzes the electro-oxidation/electroreduction of a

substrate to an electrochemically detectable product. This mode was

firstly demonstrated by the Heller group [28]. In the system, bonding

of biotinylated HRP to avidin covalently attached to an electron-

conducting redox hydrogel resulted in the “wiring” of the enzyme,

that is, its electrical connection to the electrode. The currents flow as

a result of continuous electroreduction of H

2

O

2

, electrocatalyzed by

the HRP label of an oligonucleotide strand when