A compound having the structure: or wherein SIG is a signaling molecule selected from a fluorophore, a luminescent moiety, an enzyme, a catalytic antibody, a ribozyme or a pro-enzyme, wherein each AA is independently an amino acid, PTM is a post-translational modification on any of the amino acids, n is an integer representing the total number of amino acids, wherein n is from 1 to 200, and m is an integer from 1 to 10, wherein each R 1 is independently a hydrogen, a halogen, a reducible nitrogen-containing group, or an amino group with an electron-deficient moiety, a cyano group, an isocyano group, a thiocyano group, an isothiocyano group, an azido group (N 3), a trihalomethyl group (CX 3, where X is a halogen); a sulfonate group (SO 3 R 3), a sulfate group (OSO 3 R 3), a carboxyl group (CO 2 H), a carbonyl group (COR 3), an ester group (CO 2 R 3 or OCOR 3), an amido group (CONR 3 2 or NR 3 COR 3), a carbamate group (NR 3 CO 2 R 3), a phosphate group (OPO 3 R 3 3), a phosphonate group (PO 3 R 3 2), an amino group (NR 3 2), an alkoxy group (OR 3), a thiol group (SR 3), a sulfoxy group (SOR 3), a sulfone group (SO 2 R 3), a sulfonamide group (SO 2 NR 3 2), a phosphino group (PR 3 2), or a silane group (SiR 3 3), wherein n is 0, 1, 2, 3 or 4, wherein R 2 is a hydrogen, an unsubstituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group, a substituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group wherein one or more C, CH or CH 2 groups are substituted with an O atom, N atom, S atom, NH group, CO group, OCO group or CONR 3 group, or an unsubstituted or substituted aromatic group, wherein each R 3 is independently a hydrogen, an unsubstituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group, a substituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group wherein one or more C, CH or CH 2 groups are substituted with an O atom, N atom, S atom, or NH group, or an unsubstituted or substituted aromatic group, wherein an enzyme involved in post-translational modification is capable of adding or removing the PTM, and, when the PTM is removed, a protease or peptidase is capable of removing the amino acid sequence, allowing self-cleavage of the self-immolative structure SI bound to SIG such that SIG has a reduced signal relative to the signal of SIG without SI, wherein PTM is -OH and wherein the enzyme is a protein kinase and -OH is a hydroxyl moiety on a serine, threonine, or tyrosine that is a target for phosphorylation by the kinase, or PTM is -OPO 3 2-, and wherein the enzyme is a phosphatase and -OPO 3 2- is a phosphate moiety on a serine, threonine, or tyrosine that is a target for dephosphorylation by the phosphatase. wherein SIG is a signaling molecule selected from a fluorophore, a luminescent moiety, an enzyme, a catalytic antibody, a ribozyme or a pro-enzyme, wherein each AA is independently an amino acid, PTM is a post-translational modification on any of the amino acids, n is an integer representing the total number of amino acids, wherein n is from 1 to 200, and m is an integer from 1 to 10, wherein each R 1 is independently a hydrogen, a halogen, a reducible nitrogen-containing group, or an amino group with an electron-deficient moiety, a cyano group, an isocyano group, a thiocyano group, an isothiocyano group, an azido group (N 3), a trihalomethyl group (CX 3, where X is a halogen); a sulfonate group (SO 3 R 3), a sulfate group (OSO 3 R 3), a carboxyl group (CO 2 H), a carbonyl group (COR 3), an ester group (CO 2 R 3 or OCOR 3), an amido group (CONR 3 2 or NR 3 COR 3), a carbamate group (NR 3 CO 2 R 3), a phosphate group (OPO 3 R 3 3), a phosphonate group (PO 3 R 3 2), an amino group (NR 3 2), an alkoxy group (OR 3), a thiol group (SR 3), a sulfoxy group (SOR 3), a sulfone group (SO 2 R 3), a sulfonamide group (SO 2 NR 3 2), a phosphino group (PR 3 2), or a silane group (SiR 3 3), wherein n is 0, 1, 2, 3 or 4, wherein R 2 is a hydrogen, an unsubstituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group, a substituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group wherein one or more C, CH or CH 2 groups are substituted with an O atom, N atom, S atom, NH group, CO group, OCO group or CONR 3 group, or an unsubstituted or substituted aromatic group, wherein each R 3 is independently a hydrogen, an unsubstituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group, a substituted straight-chain, branched or cyclic alkyl, alkenyl or alkynyl group wherein one or more C, CH or CH 2 groups are substituted with an O atom, N atom, S atom, or NH group, or an unsubstituted or substituted aromatic group, wherein an enzyme involved in post-translational modification is capable of adding or removing the PTM, and, when the PTM is removed, a protease or peptidase is capable of removing the amino acid sequence, allowing self-cleavage of the self-immolative structure SI bound to SIG such that SIG has a reduced signal relative to the signal of SIG without SI, wherein PTM is -OH and wherein the enzyme is a protein kinase and -OH is a hydroxyl moiety on a serine, threonine, or tyrosine that is a target for phosphorylation by the kinase, or PTM is -OPO 3 2-, and wherein the enzyme is a phosphatase and -OPO 3 2- is a phosphate moiety on a serine, threonine, or tyrosine that is a target for dephosphorylation by the phosphatase.