Tubes for detection of cholinesterase inhibitors—Unique effects of Neusilin on the stability of butyrylcholinesterase-impregnated carriers

[Display omitted] •Higher stability of the immobilized enzyme was achieved•Positive effect of Neusilin on color intensity and enzyme stability was confirmed•New parameter for difference in color change during Ellman’s reaction was utilized Detection tubes are small devices for the colorimetric enzymatic detection of cholinesterase inhibitors such as sarin, soman, VX nerve agents and substances denoted as Novichok. These detectors contain carriers in the form of pellets with immobilized cholinesterase, substrate and detection reagent. Their advantages are portability, sensitivity and simplicity, enabling fast detection of such compounds from air and water in case of a terrorist attack or war. In general, maintaining the stability of an enzyme for a longer time is very problematic; therefore, its further enhancement is required for safety and financial reasons. In this study, the stability of our patented carriers in the form of pellets with immobilized butyrylcholinesterase containing an increasing amount of the unique sorbent Neusilin® US2 was evaluated. The samples containing Neusilin maintained the stability of the immobilized enzyme for a longer time even at higher temperature and humidity than the currently commercially used carrier without Neusilin, allowing improved detection of nerve agents.