Stimuli-responsive polystyrene derivative for a turbidity-based detection of a nerve agent mimic

Abstract

Nerve agents, toxic organophosphorus compounds used in chemical warfare, present significant threats to security and public health. These agents disrupt physiological processes by covalently binding to acetylcholinesterase and blocking its ability to break down the neurotransmitter acetylcholine. Despite international efforts to eliminate such weapons, nerve agents continue to be employed due to their ease of production and stability. Their colorless, odorless nature, combined with their rapid action, underscores the importance of developing efficient detection techniques. Traditional detection methods, such as mass spectrometry, rely on the use of bulky, complex equipment and sample preparation procedures. Recent progress in the development of colorimetric and fluorescent probes has enabled direct visual confirmation of nerve agents without the need for such instrumentation. Building on these advancements, we present a turbidity-based approach to detect nerve agent mimics in water. Our method employs a polymer that, upon reacting with a nerve agent mimic, transforms from a water-insoluble polymer to a water-soluble polymer. This change causes a turbid polymer dispersion in water to become clear when exposed to a nerve agent mimic, offering a clear visual signal and a turn-on response in terms of light transmission. The method, which forgoes the need for spectroscopy, represents a platform for the future integration of the transparency-based detection scheme into sensor devices.

Graphical abstract

A schematic illustration of the turbidity-based sensing used in this study and the corresponding digital photographs of the opaque dispersion of P1 in water along with photographs taken after the injection of DCNP