In the present study, the nanotubes of 5-(4-hydroxyphenyl)-10, 15, 20-tri(4-chlorophenyl) porphyrin (p-HTCIPP) (1) and 5-(4-hydroxyphenyl)-10, 15, 20-tri(4-chlorophenyl) porphyrin cobalt (p-HTCIPPCo) (2) were successfully prepared by using anodize alumina oxide (AAO) template method. The p-HTClPP and p-HTClPPCo nanotubes have been confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), electronic absorption spectra, fluorescence spectroscopy, fourier transform infrared spectroscopy (FT-IR), low-angle X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) techniques. Both p-HTClPPCo and p-HTCIPP nanotubes showed excellent sensitivity, reproducibility and selectivity toward NO2. Especially the prepared sensor of p-HTClPPCo nanotubes exhibited faster response/recovery characteristics and lower detection limit of NO2 (up to 500 ppb) than that of p-HTClPP nanotubes, which pave a new avenue in the gas sensitive field. (C) 2016 Elsevier Inc. All rights reserved.