Electrochemical Biosensors

November 7, 2014 13:8 PSP Book - 9in x 6in 04-Serge-Cosnier-c04

108 Amperometric Enzyme Electrodes

glutarate, while GPT transforms 2-oxo-glutarate into glutamate in

the presence of L-analine. As a consequence, the resulting glutamate

biosensor based on the amperometric detection of H

2

O

2

led to a

1000-fold increase in sensitivity for the bienzyme configuration

compared to the monoenzyme one, the detection limit being

subnanomolar (0.2 nM) [35].

The combination of several enzymes working in cascade can also

be considered to amplify the signal by recovering more electrons

for a single substrate molecule. This strategy was recently used

in the field of enzymatic ...