Pt-grown carbon nanofibers for detection of hydrogen peroxide

Removal of left-over catalyst particles from carbon nanomaterials is a significant scientific and technological problem. Here, we present the physical and electrochemical study of application-specific carbon nanofibers grown from Pt-catalyst layers. The use of Pt catalyst removes the requirement for any cleaning procedure as the remaining catalyst particles have a specific role in the end-application. Despite the relatively small amount of Pt in the samples (7.0 +/- 0.2%), they show electrochemical features closely resembling those of polycrystalline Pt. In O-2-containing environment, the material shows two separate linear ranges for hydrogen peroxide reduction: 1-100 M and 100-1000 M with sensitivities of 0.432 A M-1 cm(-2) and 0.257 A M-1 cm(-2), respectively, with a 0.21 M limit of detection. In deaerated solution, there is only one linear range with sensitivity 0.244 A M-1 cm(-2) and 0.22 M limit of detection. We suggest that the high sensitivity between 1 M and 100 M in solutions where O-2 is present is due to oxygen reduction reaction occurring on the CNFs producing a small additional cathodic contribution to the measured current. This has important implications when Pt-containing sensors are utilized to detect hydrogen peroxide reduction in biological, O-2-containing environment.