CHEMICAL DETECTION OF NERVE AGENT BY A TWO STEP DOSIMETER SYSTEM BASED ON ENZYME INHIBITION INDICATED BY FLUORESCENCE

THE LONG TERM OBJECTIVE IS TO DEVELOP A RAPID "NERVE AGENT" DOSIMETER DETECTION SYSTEM AS SIMPLE, FIELDABLE AND RUGGED AS A PIECE OF WET, CHEMICALLY IMPREGNATED CLOTH. IT WOULD HAVE THE SENSITIVITY TO DETECT LESS THAN 1 NG/M(3) OF NERVE AGENT IN THE FIELD AND THE HIGH SPECIFICITY TO AGENT PHYSIOLOGICAL FUNCTION INHERENT TO ENZYME INHIBITION. EACH DOSIMETER WOULD WEIGHT LESS THAN 1/4 OZ. AND COST LESSTHAN $0.50. THIS LONG TERM OBJECTIVE WILL BE ACCOMPLISHED BY OUR UNIQUE METHOD OF SPLITTING DETECTION INTO TWO STEPS, THAT CAN EACH BE INDEPENDENTLY INVESTIGATED. THE FIRST STEP IS EXPOSURE OF THE DOSIMETER (AN ENZYME IMPREGNATED WICK) TO THE INHIBITING AGENT. THE SECOND STEP IS READ-OUT AFTER APPLYING A "DEVELOPING" CHEMICAL TO THE DOSIMETER. THIS "DEVELOPER" FLUORESCES ON CONTACT WITH UNINHIBITED ENZYME, INDICATING THE AMOUNT OF AGENT TO WHICH THE DOSIMETER WAS EXPOSED. THE FLUORESCENCE IS THEN READ-OUT WITH A RUGGED, INEXPENSIVE POCKET FLUORIMETER. THE SPECIFIC OBJECTIVE OF PHASE I IS TO INVESTIGATE THE PERFORMANCE, STABILITY AND REPRODUCIBILITY OF THE CHEMISTRY OF THE SECOND STAGE OF THE PROPOSED METHOD.