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-containing environment, the material shows two separate linear ranges for hydrogen peroxide reduction: 1-100 μM and 100-1000 μM with sensitivities of 0.432 μA μM cm and 0.257 μA μM cm, respectively, with a 0.21 μM limit of detection. In deaerated solution, there is only one linear range with sensitivity 0.244 μA μM cm and 0.22 μM limit of detection. We suggest that the high sensitivity between 1 μM and 100 μM in solutions where O 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-containing environment.