Functionalized double-chain surfactant 1 (2-hydrazino-N-methyl-N,N-didodecyl-2-oxoethanaminium bromide) was synthesized, and its small unilamellar vesicles were characterized by dynamic laser light scattering and differential scanning calorimetry. In a pH 9.0 berate buffer at 25 degrees C, vesicular 1 and 2 (O-methyl S-benzyl phenylphosphonothioate), a simulant for the chemical warfare agent VX [O-ethyl S-(2-N,N-diisopropylamino)ethyl methylphosphonothioate] reacted to give anion 3a (S-benzyl phenylphosphonothioate) and cations 11-13 (2-(2-N-methylhydrazino)-N＇-methyl-N＇,N＇-didodecyl-2-oxo-ethanaminium, 2-(2-N,N-dimethylhydrazino)-N＇-methyl-N＇ and 2-[1-hydroxy-2- (N-methyl-N,N-didodecylammonio)ethylidene]-N＇,N＇,N＇-trimethylhydrazinium, respectively) by S(N)2 substitution on the Me group of 2. This reaction was accompanied by the precipitation of anion 3a with surfactant cations, which resulted in wounding/destruction of the vesicles. The combination of vesicle damage and reaction of 2 suggests the potential of vesicular systems for simultaneous signaling and decontamination of chemical agents. Ester 2 hydrolyzed in 0.10 M NaOH at 25 degrees C to give anions 3a and 10 (O-methyl phenylphosphonothioate) in a 38:62 ratio, respectively.