In this study, a simple and one-pot pyrolysis strategy is developed for the mass production of Fe, N-incorporated carbon nanotubes in situ grown on 3D porous carbon foam (denoted as Fe-Phen-CFs), which provides highly active Fe-N and doped-N species, and a large surface area with exposed active sites. The obtained composite exhibits intrinsic peroxidase-like catalytic activities. With the Fe-Phen-CFs as the catalyst, the peroxidase substrate of terephthalic acid (TA) can be oxidized to the fluorescent product of hydroxyterephthalate (HTA) by H2O2, which provides a unique strategy for fluorescence detection of H2O2. With such a process, as low as 68 nM H2O2 could be detected with a linear range from 0.1 to 100 μM. Meanwhile, by integrating glucose oxidase on the Fe-Phen-CFs composite, sensitive detection of glucose is also achieved with a linear range from 0.5 to 200 μM and a limit of detection of 0.19 μM. Most importantly, such a novel TA/Fe-Phen-CFs system can be successfully applied to glucose determination in real human serum samples. The unique nature and 3D structure of the Fe-Phen-CFs composite makes it promising for the fabrication of low-cost, high-performance biosensors.