Alcohol sensing capability of platinum octaethylporphyrin embedded into a fluorinated polyimide

Amongst the optical probes used for oxygen detection, the photoluminescent dye platinum octaethylporphyrin (PtOEP) is the most widely used owing to its high sensitivity, large Stokepsilas shift and long lived excited state. On the other hand, a strong decrease in the luminescence yield of platinum porphyrins was also found in the presence of several solvents and the quenching effect was related to solvent polarity. In this work, the alcohol sensing capability of PtOEP encapsulated into a fluorinated polyimide is explored for the first time. The films were analyzed by absorption, emission and reflectance spectroscopy and the sensing capabilities of the materials toward ethanol and methanol vapors were tested. The emission intensity of PtOEP undergoes a visible decrease upon exposure to alcohol vapor and a fast recovery upon exposure to nitrogen flow. The kinetic profiles highlight the good behavior of the films as related to sensitivity, response and recovery speed and reproducibility.