Fluorescent probe based on a Cu²⁺ bridging strategy for the specific recognition and differentiation of TKX-50 and...

Fluorescence sensing technology has gained considerable interest for explosive detection due to its high sensitivity and on-site applicability. The continuous emergence of novel energetic materials are promoting the extension of the research scope of fluorescent probes from traditional explosives to these emerging threats. This study reports a multifunctional coumarin-based fluorescent probe (E)-N'-((7-(diethylamino)-2-oxo-2H-chromen-3-yl) methylene)-2-naphthohydrazide (CNH). It can specifically recognize Cu²⁺ through the "on-off" fluorescence response. The resulting [CNH-Cu²⁺] complex acts as a secondary probe, achieving sensitive detection and visual differentiation of the novel energetic materials TKX-50 and NTO through dual-channel signal outputs combining fluorescence recovery and naked-eye color change. The detection limits for the three target compounds were 0.2520 μM, 0.1471 μM and 0.3777 μM, respectively, exhibiting rapid response and anti-interference ability. Moreover, the probe was successfully applied to real water analysis, test-strip detection, and live-cell imaging, demonstrating its detection capabilities across environmental and biological domains.