Targeting Fluoride Ions for Nerve Agent Detection

Nerve Agent Detection
The auto-inductive cascade for the detection of nerve agent surrogate, DFP, through fluoride (signal) amplification. Figure courtesy of Chemistry – A European Journal

Current chemical detectors are either complex instruments requiring technical user training, or rely on special low-cost detection paper which may give false positives depending on environmental factors. Fluorescence-based detection may be instrumental in closing these gaps by providing an accurate, easy-to-use tool to help responders quickly identify threats.

Nerve agents work by disrupting the mechanisms that allow nerves to communicate with organs. A common family of these agents, organophosphorous compounds, include two main classes: fluoride-containing “G series” and sulfur-containing “V series”.

Professor Eric Anslyn, Ph.D., at the University of Texas at Austin (UT Austin), is developing new detection techniques by targeting the fluoride ions released by G-series agents, such as sarin, soman and cyclosarin.

Managed by the Defense Threat Reduction Agency’s Anthony Esposito, Ph.D., UT Austin researchers introduced a novel approach to visually detect fluoride ions through three steps: generation, amplification and sensing. This approach enhances detection capabilities for the Department of Defense by successfully merging multiple, complex reactions for accurately detecting trace amounts of harmful toxins.

The team is using diisopropyl fluorophosphate (DFP), a nerve agent surrogate, to mimic response before testing the methodology against toxins. The new approach is ultrasensitive due to an auto-inductive cascade, a process that generates six fluoride ions for each ion released in the initial reaction between the DFP and benzaldoxime. This process makes detection of trace amounts of toxins possible.

Utilizing both colorimetric and fluorescent detection, fluoride ions are tracked throughout the cascade. Both detection techniques demonstrate promise for detecting G series nerve agents.

Anslyn’s team is continuing to explore novel methodologies for visual identification of nerve agents. Currently, the team is studying a new auto-inductive cascade that uses benzoyl fluoride rather than benzaldoxime, to increase the reaction speed of nerve agents. These efforts will allow responders to quickly identify threats and shorten response times and improve safety.

Read more: New Autoinductive Cascade for the Optical Sensing of Fluoride: Application in the Detection of Phosphoryl Fluoride Nerve Agents.

Article adapted from original by the Defense Threat Reduction Agency’s Chemical and Biological Technologies Department. Edited for context and format by CBRNE Central.