A novel method for the preparation of titania sol–gel derived oxygen sensors based on the ruthenium(II) dye, [Ru(bpy)3]2+, is described. A titania sol–gel paste film was cast onto microscope slides, and the dye ion-paired to the deprotonated, hydroxylated groups on the film's surface from an aqueous solution of the dye at pH 11. The resulting sensor film is extremely oxygen sensitive, with a PO2 (S = 1/2) value (i.e. the partial pressure of oxygen required in order to reduce the original, oxygen free, luminescence intensity by 50%) of 0.011 atm. The sensor undergoes 95% response to oxygen in 4 s, and shows 95% recovery of its luminescence in argon within 7 s.
Mills, A., Graham, A., & O'Rourke, C. (2014). Novel titania sol-gel derived film for luminescence-based oxygen sensing. Sensors and Actuators B: Chemical, 190, 907-912, Impact Factor: 4.1. https://doi.org/10.1016/j.snb.2013.08.097