Fabrication of a re-useable ionic liquid-based colorimetric organo nanosensor for detection of nerve agents'...

Nerve agents are highly poisonous organophosphorus chemicals, and the possibility of being used in terrorist attacks seriously threatens public safety. Thus, developing quick and straightforward detection techniques for these dangerous substances is paramount for the scientific communities. In this contribution, we have fabricated a sensitive and easily applicable ionic liquids (ILs) based colorimetric sensor for detecting various nerve agents' stimulants in solution and gas phases, respectively, based on methyl orange (MO)-based IL ([P₆₆₆₁₄]⁺[MO]^-) derived from MO dye and trihexyltetradecylphosphonium chloride (P₆₆₆₁₄Cl) by a simple ion exchange mechanism. The developed [P₆₆₆₁₄]⁺[MO]^- and water-suspended [P₆₆₆₁₄]⁺[MO]^- nanoparticles are found to be very much sensitive to detecting various nerve agents' stimulants having detection limits in the μM range in any medium and could be identified based on the response times which is found to be superior to many chemosensors available in the literature. The naked eye observed a distinct color change from yellow to fuchsia in the presence of nerve agents' stimulants, which shows better sensitivity than the free organic indicator. Furthermore, a facile test strip with [P₆₆₆₁₄]⁺[MO]^- and water-suspended [P₆₆₆₁₄]⁺[MO]^- NPs has been fabricated that can achieve visual detection of various nerve agents' stimulants within the stockpiles of other analogous harmful analytes. Also, a dip-stick experiment has been performed to detect harmful toxic analytes vapor. The effectiveness of [P₆₆₆₁₄]⁺[MO]^- and water-suspended [P₆₆₆₁₄]⁺[MO]^- NPs in identifying and quantifying various nerve agents' stimulants demonstrated its potential for usage as a signal tool for real sample analysis.