Nano-molar level hydrogen peroxide detection by horseradish peroxidase adsorbed cup-stacked carbon nanotube electrodes and applications to L-glutamate detection.

We have developed a simple fabrication method of a highly sensitive direct electron transfer-type electrochemical biosensor for hydrogen peroxide by use of cup-stacked carbon nanotubes (CSCNTs). The CSCNTs, formed by stacking of cup-shaped carbon units, has larger internal space and more hydrophilic edges, thanks to the presence of functional groups containing oxygen (e.g.