A self-degradable hydrogel sensor for a nerve agent tabun surrogate through a self-propagating cascade

Nerve agents that irreversibly deactivate the enzyme acetylcholin- esterase are extremely toxic weapons of mass destruction. Thus, developing methods to detect these lethal agents is important. To create an optical sensor for a surrogate of the nerve agent tabun, as well as a physical barrier that dissolves in response to this analyte, we devise a network hydrogel that decomposes via a self-propagating cascade. A Meldrums acid-derived linker is incor- porated into a hydrogel that undergoes a declick reaction in response to thiols, thereby breaking network connections, which re- leases more thiols, propagating the response throughout the gel. A combination of chemical reactions triggered by the addition of the tabun mimic initiates the cascade. The dissolving barrier is used to release dyes, as well as nanocrystals that undergo a spontaneous aggregation. Thus, this sensing system for tabun generates a phys- ical response and the delivery of chemical agents in response to an initial trigger.