Nanowires of Zn(II) 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine (ZnPcOC8) and nanoflowers of Cu(II) 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine (CuPcOC8) have been uniformly grown onto glass substrate by employing a cost effective solution based self-assembly technique. The nanowires and nanoflowers were characterized by XRD, SEM and UV-Visible absorption spectroscopy. It has been demonstrated that these nanowires and nanoflowers were highly sensitive towards Cl2 at room temperature with a detection limit as low as 5 ppb. The response of nanowires and nanoflowers varied linearly from 93% to 715% and 85% to 550% for 5–1500 ppb of Cl2. Raman spectroscopic and XPS studies revealed that the central metal ions of ZnPcOC8 and CuPcOC8 were the predominant absorption sites for Cl2. The results emphasized the application of these nanostructures as low cost and highly sensitive room temperature Cl2 sensors.
