Analysis of Nerve Agents Through a Modified Method of Cholinesterase Assessment Using Artificial Neuronal Networks

Abstract

A simple colorimetric biosensor, which uses the modified Ellman's reaction, enables selective analysis of nerve agents based on a different ability of bispyridinium oximes to reactivate enzyme-inhibitor complexes in the phase before dealkylation. The analysis was made based on spectral data of reflectance of the surface of a cotton cloth reaction zone of biosensor with immobilized and stabilized enzyme after inhibition and subsequent reactivation. The evaluation of measured data was made based on a method of artificial neuronal networks. The individual inhibitors from the groups of three nerve agents were identified: sarin, soman, tabun, cyclosarin, agent VX and its Russian analogue, R-33.

Modified Biosensor for Cholinesterase Inhibitors with Guinea Green B as the Color Indicator

“…Recently, however, acetylcholine and butyrylcholine have largely been replaced with acetylthiocholine or butyrylthiocholine, respectively, in which case thiocholine is produced instead of choline. Thiocholine changes the color of redox indicators, such as Ellman’s reagent [ 9 , 10 , 11 ], 2,6-dichlorophenolindophenol [ 12 ] or its analogues [ 13 ], or triphenylmethane dyes such as Guinea Green B and Malachite Green [ 4 , 14 , 15 ]. Chromogenic substrates, e.g., 2,6-dichlorophenolindophenyl acetate [ 16 ] and indoxyl acetate [ 17 ], which decompose directly on colored products, are frequently used alternatives.…”