481Nanobiosensors
8.5.1 Uric Acid Biosensor
Zhang et al. (2006) performed UA (C
5
H
4
N
4
O
3
) biosensing with uricase-ZnS
QD/-Cyst (HSCH
2
CH
2
NH
2
) assembly; uricase is a peroxisomal liver enzyme
that catalyzes the oxidation of UA to allantoin during purine catabolism.
Covalent binding of uricase and -Cyst occurs through the free carboxyl
groups on the surface of ZnS QDs. Properties of carboxyl group functionalized
ZnS QDs such as solubility, conductivity, and more binding sites for increased
enzyme loading imparted high electrocatalytic performance to the sensor.
8.5.2 Hydrogen Peroxide Biosensor
Where are H
2
O
2
measurements required? The determination of hydrogen perox-
ide content is of great importance in many elds, including ...