A new convenient strategy to fabricate a third-generation hydrogen peroxide biosensor was described. The screen-printed carbon electrode (SPCE) was first modified with a layer of 4-nitrophenyl assembled from the 4-nitroaniline diazonium salt synthesized in situ in acidic aqueous solution. Next, the nitro groups were converted to amines followed by crosslinking to the horseradish peroxidase (HRP) by glutaraldehyde. The redox chemistry of the active center of the HRP was observed and the HRP-modified electrode displayed electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) without any mediators. H2O2 was determined in a linear range from 5.0 μM to 50.0 μM, with a detection limit of 1.0 μM. Furthermore, the biosensor exhibited fast amperometric response, good reproducibility and long-term stability. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
|Publication status||Published - 1 Jul 2009|
- Diazonium salt
- Direct electrochemistry
- Horseradish peroxidase
- Hydrogen peroxide
- Screen-printed carbon electrode