An Auto-Inductive Cascade for the Optical Sensing of Thiols in Aqueous Media: Application in the Detection of a VX Nerve Agent Mimic.

A new auto-inductive protocol employs a Meldrum's-acid-based conjugate acceptor (1) as a latent source of thiol for signal amplification, as well as optical detection of thiols. The auto-induction is initiated by a thiol-disulfide exchange that leads to the generation of β-mercaptoethanol, which in turn decouples the conjugate acceptor to release more thiols, resulting in a self-propagating cycle that continues until all the conjugate acceptor is consumed. Using 1 in a two-step integrated protocol yields a rapid, sensitive, and precise diagnostic assay for the ultratrace quantitation of a thiophosphate nerve agent surrogate.