2,4-Dinitrophenylhydrazine (DNPH) is widely present in the ecological environment and has great harmful effects on humans, so it is necessary to detect DNPH in environmental samples. Chitosan, the second abundant renewable biological material in natural, has the advantages of wide sources, good biodegradability and good biocompatibility. Naphthalimide is a kind of classical fluorophore and has widely applications in fluorescent probe field. In this paper, a new fluorescent probe CTS-NA-OAc for DNPH detection was developed, which was constructed by using chitosan as skeleton and naphthalimide as the fluorophore. This probe displayed a highly specific “turn-off” fluorescence response toward DNPH, accompanied by the fluorescence color change from green to colorless. Its detection limit for DNPH was calculated to be 4.9 × 10⁻⁷ M and much lower than that of the corresponding model compound NA-OAc. The interference experiments showed that other competing analytes have no influence on the detection of DNPH in a complex environment. In addition, the coordination mechanism of CTS-NA-OAc with DNPH was investigated by ¹H NMR titration and DFT calculations. Inspired by the above prominent performances, the probe CTS-NA-OAc was successfully applied to the detection of DNPH in real water and soil samples.

2,4-二硝基苯肼（DNPH）广泛存在于生态环境中，对人体的危害很大，因此有必要对环境样品中的DNPH进行检测。壳聚糖是自然界中第二丰富的可再生生物材料，具有来源广、生物降解性好、生物相容性好等优点。萘酰亚胺是一种经典的荧光团，在荧光探针领域有着广泛的应用。在本文中，一种新的荧光探针CTS-NA-OAc以壳聚糖为骨架，萘二甲酰亚胺为荧光基团构建的DNPH检测试剂盒。该探针对 DNPH 显示出高度特异性的“关闭”荧光响应，伴随着荧光颜色从绿色变为无色。经计算，其对 DNPH 的检测限为 4.9 × 10 ^-7 M，远低于相应模型化合物NA-OAc 的检测限。干扰实验表明，其他竞争分析物在复杂环境中对DNPH的检测没有影响。此外，通过¹ H NMR 滴定和 DFT 计算研究了CTS-NA-OAc与 DNPH的配位机制。受上述突出表现的启发，探头CTS-NA-OAc成功应用于实际水样和土壤样品中DNPH的检测。