FIBER-OPTIC FLUOROSENSOR FOR OXYGEN AND CARBON-DIOXIDE

The capability of fiber-optic light guides to transmit a variety of optical signals simultaneously has been exploited to construct an optical fiber sensor for measurement of both oxygen and carbon dioxide. The oxygen-sensitive material (a Kieseigel-adsorbed fluorescent metal-organic complex) and the CO2-sensitive material (an immobilized pH indicator in a buffer solution) are entrapped in a gas-permeable polymer matrix that is attached to the distal end of the fiber. Both indicators have the same excitation wavelength (in order to avoid energy transfer) but quite different emission maxima. The two emission bands can easily be separated with the help of interference filters and give independent signals.