Patent ID: 8158438

Claim:
A method for the determination of the concentration of a nonvolatile analyte present in an aqueous sample medium using an optical sensor which contains in at least one sensor layer an immobilized luminescent indicator dye that exhibits luminescence in a dry state when excited and that has optical characteristics that vary with the concentration of the analyte contained in the aqueous sample medium, the method comprising: calibrating the optical sensor by a single-point calibration having only one calibration step, the only one calibration step comprising measuring luminescence of the optical sensor as a dry optical sensor without the use of calibrating media, yielding a user-site dry calibration value; obtaining a luminescence measurement value of the optical sensor as a wet optical sensor in contact with the aqueous sample medium; and deducing the concentration of the non-volatile analyte from the luminescence measurement value, the user-site dry calibration value, and a predetermined wet to dry relationship that is supplied together with the optical sensor and is derived from a factory-site wet calibration value and a factory-site dry calibration value.