A novel optical oxygen sensing system based on triplet-triplet reflectance of fullerene C60-polystyrene film by time-resolved spectroscopy using diffuse reflectance laser flash photolysis

A new optical oxygen sensing system based on the triplet lifetimes of C-60 in polystyrene (PS) film under different oxygen concentrations was developed by using OPO-Nd-YAG laser flash photolysis. The lifetime of the photoexcited triplet state of C-60-PS film decreases with increasing oxygen concentration, indicating that the photoexcited triplet state of C-60 in the PS film was quenched effectively by oxygen. A Stern-Volmer plot of C-60 in PS film exhibits considerable linearity (r(2) = 0.999), K-sv is estimated to be 0.50 %(-1). The quenching rate constant for the photoexcited triplet state of C-60 in the PS film by oxygen, k(q), is 5.0 x 10(3) %(-1) s(-1). A highly sensitive oxygen sensor based on the photoexcited triplet state of C-60 molecules by oxygen has been developed using time-resolved spectroscopy with laser flash photolysis.