Enhanced emission based optical carbon dioxide sensing in presence of perfluorochemicals (PFCs)

An emission based simple and fast method has been proposed for the determination of gaseous and dissolved CO2. Perfluorochemicals (PFCs), also known as medical gas carriers have been used for the first time together with newly synthesized fluorophore; 4-[(p-N,N-dimethylamino)benzylidene]-2-phenyloxazole-5-one (DPO), in ethyl cellulose matrix. In the first stage of the study precise determination of the acidity constant (pKa) of the DPO has been performed in the employed polymer matrix. In second stage, the response of the sensor composition to gaseous and dissolved CO2 has been evaluated in the absence and presence of the PFC. It should be noted that the solubility of CO2 in fluorocarbons is about 10–20 times as that observed in the parent hydrocarbons or in water, respectively, and once doped into the sensing film, considerably enhance the response of the sensing agent.