A third-generation hydrogen peroxide biosensor based on horseradish peroxidase cross-linked to multi-wall carbon nanotubes

A novel third generation biosensor for hydrogen peroxide (HP) was constructed by crosslinking horseradish peroxidase (HRP) onto an electrode modified with multi-wall carbon nanotubes (MWNTs). Glutaraldehyde and bovine serum albumin were used to cross-link HRP and the MWNTs. Scanning electron microscopy revealed that HRP was evenly distributed on the surface of the nanotubes. Factors influencing the performance of the biosensor were studied in detail. The biosensor exhibited a fast amperometric response (2.0 s) to HP which is linear in the concentration range from 9.5 mM to 0.95 mu M. The detection of limit is 0.4 mu M. The sensor exhibits good stability and durability (on testing 0.1 mM solution of HP over a period of 10 days), with a long-term relative standard deviation of < 5%.