Porphyrin nanotubes film for optical gas sensing

Abstract

The purpose of this work was to develop a novel morphology of gas sensing layer based on porphyrin sheets and nanotubes and to investigate the physical-chemistry and sensing properties of the porphyrin layer. In the present work the porphyrins nanoparticles were synthesized by ionic selfassembly in aqueous solutions of two oppositely charged non-metal porphyrins, namely, the anionic Meso-tetra (4-sulfonatophenyl) porphine dihydrochloride (TPPS4) and cationic Meso-tetra (4-pyridyl) porphine (T4MPyP) and an ethanol was not added to the solution. We investigated in details the nanosheets and nanotubes formation and behaviors of aggregation induced by mixing an anionic TPPS4 and cationic T4MPyP acidic solutions by means of the UV-vis spectroscopy and aggregates structure and morphology by transmission electron microscopy (TEM), scanning electron microscopy (SEM). The sensing capabilities of the samples have been finally evaluated by exposing the films to the different concentration of ethanol atmospheres.