Development of Dissolved Oxygen Sensor Based on Time-domain Lifetime Measurement with a Sensing Film Fabricated by...

A dissolved oxygen sensor was developed based on time-domain lifetime measurement with an oxygen sensing film. The oxygen sensing film was fabricated by embedding PtOEP in a highly stable and highly hydrophobic fluorinated matrix synthesized from methacrylate, fluorinated methacrylate, and 3-(tris(trimethylsilyloxy)silyl)propyl methacrylate via free radical polymerization. The fluorinated methacrylate provided the high stability and the 3-(tris(trimethylsilyloxy)silyl)propyl methacrylate provided the extra hydrophobicity. The PtOEP was excited using pulsed signals from a green-light LED and the fluorescence lifetime was evaluated by time-domain lifetime measurement. The dynamical quenching of fluorescence response by dissolved oxygen was calibrated using the Stern-Volmer plot with a high $$ ratio of 5.68 and a Stern-Volmer constant of 0.112 mg^-1  dm³ . It was demonstrated that the dissolved oxygen sensing film showed high stability under the varied excitation intensity and long-term stability in the accelerated aging experiment and the repeated freeze-thaw-cycling tests.