Superoxides enzyme-based biosensors

Enzyme-based biosensors are very suitable for the antioxidant status evaluation, since they show excellent selectivity for biological substances and can directly determine and/or monitor antioxidant compounds in a complex media such as biological or vegetable samples without needing a prior separation step. During the course of the catalytic reaction on the electroactive substrates, the current produced at an applied potential is related to the concentration of a specific biomarker, for which the biosensor is selective. HRP-based biosensors for antioxidant status evaluation have been applied in the detection of superoxide radical [119], nitric oxide [120], glutathione [119, 121], uric acid [122, 123], and phenolic compounds [124—126],... 

Also, third-generation biosensors for superoxide anion (O ) have been developed based on superoxide dismutase (SOD) immobilised by thin silica-PVA sol-gel film on a gold electrode surface [633]. The preparation of SOD electrode is easy and simple. The uniform porous structure of the silica-PVA sol-gel matrix results in a fast response rate of immobilised SOD and is very efficient for stabilising the enzyme activity. 

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