A Rhodamine-Based Probe for Detection of Nerve Agents Simulants

In this paper, a rhodamine-based fluorescent and chromogenic probe, N-(Rhodamine B)-lactam-2-aminobenzyl alcohol (RB-AB), was designed to detect nerve agent simulants. We firstly synthesized RB-AB probe by using rhodamine B and 2-aminobenzyl alcohol as main materials. Secondly, the RB-AB probe was applied to evaluate its ability to detect two nerve agent simulants, diethyl chloride phosphate (DCP) and methyl ethyl chloride phosphate (MECP). It was assumed that RB-AB could react with the nerve agent simulants through the benzyl alcohol group and then undergoes structural changes. As a result, the RB-AB detection solution shows fluorescent and color changes during detecting process. The maximum intensity of fluorescence emission increases with the addition of DCP or MECP in a dose-dependent manner. The LOD (limit of detection) of the probe is about 20 ppm for DCP. Moreover, a significant pink color change can be observed in the RB-AB system within a few seconds when detecting DCP or MECP. In conclusion, a rhodamine-based molecule as a fluorescent and chromogenic probe was developed for detecting nerve agent simulants. The RB-AB probe solutions can give rapid and off-on type optical changes including color and fluorescence when reacting with DCP or MECP. We anticipate that RB-AB probe can be used as a helpful tool for visual and fluorescent detection of nerve agents when meeting with terrorist attacks involving with these agents so that effective measures could be promptly taken to cope with the crises.