We used a versatile, well-described chemical reaction cycle in which a phthalic acid-based precursor is transiently activated into its corresponding anhydride at the expense of a molecule of EDC (1ethyl-3-(3-dimethylaminopropyl)carbodiimide, Fig. ). In the activation reaction, the precursor reacts with EDC to yield the precursor's anhydride state and EDU (1-(3-(dimethylamino)propyl)-3ethylurea) in a two-step process. The anhydride product rapidly hydrolyzes to its precursor state in the aqueous environment, i.e., the deactivation reaction. In its finite lifetime, the hydrophobization and rigidification of the molecule can induce self-assembly or, in our design, affect the stability of a DNA hairpin. Using copper-catalyzed alkyne-azide cycloaddition reaction, we modified an alkyne-bearing thymine to carry two carboxylates that serve as the precursor for our reaction cycle (modified thymine, Fig. ).