A TECHNOLOGY WILL BE DEVELOPED FOR THE PRODUCTION OF MINIATURE BIOSENSORS THAT CAN BE USED FOR IN VIVO AND IN VITRO MONITORING OF LOW MOLECULAR WEIGHT ANALYTES (<1000) SUCH AS METABOLITES, DRUGS, HORMONES, AND TOXIC SUBSTANCES.

A TECHNOLOGY WILL BE DEVELOPED FOR THE PRODUCTION OF MINIATURE BIOSENSORS THAT CAN BE USED FOR IN VIVO AND IN VITRO MONITORING OF LOW MOLECULAR WEIGHT ANALYTES (<1000) SUCH AS METABOLITES, DRUGS, HORMONES, AND TOXIC SUBSTANCES. THE TECHNOLOGY IS BASED ON FIBER OPTICS AND IMMUNOASSAY PRINCIPLES, THAT IS, A RECEPTOR IS SELECTED FOR A DRUG, AND THE QUENCHING OF A FLUORESCENTLY LABELED ANALOG OF THE DRUG IS USED TO MEASURE THE EXTENT OF BINDING BETWEEN RECEPTOR AND DRUG. WHILE IMMUNOASSAYS ARE DISCRETE TESTS, THE BIO- SENSOR TECHNOLOGY BEING DEVELOPED PROVIDES CONTINUOUS ONLINEMONITORING. THE ANTIBODY OR ITS EQUIVALENT AND A HIGH MW FLUORESCENT ANALOG ARE RETAINED IN A SELECTIVELY POROUS MICRO TEST TUBE, FORMED BY A HOLLOW DIALYSIS FIBER (-300 MICRONS DIAMETER). THE BIOSENSOR READILY RESPONDS TO EXTERNAL CONCENTRATION CHANGES OF ANALYTE DUE TO THE REVERSIBLE DISPLACEMENT OF THE FLUORESCENT ANALOG FROM THE RECEPTOR. FLUORESCENT INTENSITY IS MONITORED WITH A SINGLE OPTICAL FIBER INSERTED INTO THE HOLLOW DIALYSIS FIBER. THE USE OF FIBER OPTICS PROVIDES THE CAPABILITY FOR A WIDE VARIETY OF OPTICAL MEASUREMENTS, FOR EXAMPLE, COLORIMETRY, FLUORESCENCE, LIGHT SCATTERING, AND OPTICAL ROTATION, TO MEASURE THE EXTENT OF BINDING. EVENTUALLY, AS MINIATURE OPTIC ELECTRONIC DEVICES (SOLID STATE LASERS, PHOTO- DETECTORS, AND COUPLERS) BECOME AVAILABLE, IMPLANTABLE BIOSENSORS WILL BE PRACTICAL. APPLICATIONS FOR THESE BIOSENSORS INCLUDE: CONTINUOUS DRUG MONITORING IN INTENSIVECARE; FEEDBACK CONTROL SYSTEMS; AND MEASUREMENT OF TOXIC CHEMICALS IN THE ENVIRONMENT.