APPARATUS FOR CONTINUOUSLY MONITORING A PLURALITY OF CHEMICAL ANALYTES THROUGH A SINGLE OPTICAL FIBER AND METHOD OF MAKING

摘要

APPARATUS FOR CONTINUOUSLY MONITORING A PLURALITY OF CHEMICAL ANALYTES THROUGH A SINGLE OPTICAL FIBER AND METHOD OF MAKING A CO2/O2 or pH/O2 gas sensor comprising a single optical fiber and a method for making the same. The optical fiber carries light signals at differentwavelengths for monitoring either CO2 concentration or pH level, in combination with O2 concentration. Attached to the distal end of the fiber-optic probe is a cylindrical pellet that has one surface covered by a light reflective material (gold foil) and the other surface attached adjacent to the distal end of the optical fiber. Depending on whether the sensor is to monitor either CO2 or pH, the pellet comprises either a CO2 analyte indicator molecule or a pH analyte indicator molecule covalently bonded to a polymer matrix material. Also adjacent to the distal end of the optical fiber is disposed a second polymer matrix material which is codissolved with an O2 analyte reactive indicator molecule. The second polymer matrix material is either interposed between the cylindrical pellet and the distal end of the optical fiber or surrounds the cylindrical pellet. If pH is being measured, the distal end of the optical fiber is coated with a hydrophilicmaterial that is permeable to water. Conversely, if CO2 is being monitored, the distal end is coated with a hydrophobic material. RMA/klp 1/ABBO-4696