The development of effective approaches for detecting toxic hydrazine (N₂H₄) is of great importance for public health. In this work, a near-infrared (NIR) fluorescent probe (QLN-Hy) for trace hydrazine detection with a large Stokes shift was constructed. Hydrazine-activatable QLN-Hy displayed striking characteristics of high sensitivity (detection limit: 0.25 μM), high selectivity, as well as notable fluorescence enhancement at the NIR emission (692 nm) and large Stokes shift (104 nm). In particular, the color of QLN-Hy changed from purple to light blue, enabling the direct visualization of hydrazine in vapor and aqueous phases through the naked eye readily. Meanwhile, the practical feasibility of QLN-Hy was successfully evaluated by quantitatively detecting trace hydrazine in water samples (lake water, river water, rain water, tap water, drinking water) and mice samples (urine, serum). Importantly, probe QLN-Hy can be conveniently applied to monitor and visualizing hydrazine in cells and in vivo, clearly demonstrating its invaluable potential biological applications.

开发检测有毒肼（N ₂ H ₄ ）的有效方法对于公众健康具有重要意义。在这项工作中，构建了一种具有大斯托克斯位移的用于痕量肼检测的近红外（NIR）荧光探针（QLN-Hy ）。肼激活的QLN-Hy表现出高灵敏度（检测限：0.25 μM）、高选择性以及在近红外发射（692 nm）和大斯托克斯位移（104 nm）处显着的荧光增强的显着特征。特别是， QLN-Hy的颜色从紫色变为浅蓝色，使得可以轻松地通过肉眼直接观察气相和水相中的肼。同时，实际可行性通过定量检测水样（湖水、河水、雨水、自来水、饮用水）和小鼠样品（尿液、血清）中的痕量肼，成功评估了QLN-Hy 。重要的是，探针QLN-Hy可以方便地应用于细胞和体内肼的监测和可视化，清楚地证明了其宝贵的潜在生物学应用。