Patent ID: 7332354

Claim:
A chemical compound comprising a light emitting moiety precursor selected from the group consisting of 2-(4 hydroxyphenyl) 4H benzo[e][1,3] oxazine-4-carboxylic acid, 2-(4-hydroxyphenyl) 4,5 dihydro thiazole 5,5 dimethyl-4-carboxylic acid, luciferin and acridinium-9-carboxylic acid and a leaving group precursor selected from the group consisting of leuko-resorufin and leuko-oxazine, wherein the carbonyl group of the light emitting precursor is linked via an amide bond to a nitrogen atom of the leaving group precursor and wherein said nitrogen atom of the leaving group precursor is an oxidizable nitrogen and part of a donor-pi-donor redox system.