Optodes dioxide

Lubbers D.W., Opitz N., The pC02-/p02 optode, a new probe for measurement of partial pressure of carbon dioxide or partial pressure of oxygen in fluids and gases, Z. Naturforsch. 1975 30C 532. 

Fig. 13.2 Structure of an optode for the detection of molecular oxygen and carbon dioxide. Fluorophore I (O2) tris(2,2 -bipyridyl)ruthenium(ll) dichloride fluorophore II (CO2) l-hydroxypyrene-3,6,8-trisulfonate. Adapted from Baldini et al. [4] with permission from Springer.

Weigl BH, Holobar A, Trettnak W, Klimant I, Kraus H, O Leary P, Wolfbeis OS (1994) Optical triple sensor for measuring pH oxygen and carbon dioxide. J Biotechnol 32 127-138 Borisov SM, Klimant I (2007) Ultrabright oxygen optodes based on cyclometalated iridium (111) coumarin complexes. Anal Chem 79 7501-7509... 

Expired air contains 2 to 5% carbon dioxide Although most carbon dioxide optodes are known to be particularly slow in response, the response time of this kind of sensor is less than 0 3 s (I) for 90% of the total signal change to occur. This is obviously due to the very thin coating. Such a fast response makes it possible to instrumentally monitor the concentration of carbon dioxide in respiratory air, but also to visually observe the continuous color change (from blue to yellow and back) while breathing through the capillary... 

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