The present invention is concerned with self-immolative recognition and/or responsive systems for electrophilic compounds, especially alkylating agents, which systems may comprise disclosure or detection of the alkylating agent. The present invention is especially concerned with non-protic triggered self-immolative systems, molecules, and methods, and in particular for detection of non-protic electrophilic agents, and especially alkylating agents, for example alkyl or benzylic halides, which may be found in pesticides or fumigants, or chemical warfare agents.