The development of convenient assays for the determination of hydrazine (N₂H₄) has drawn significant attention due to the high toxicity of this substance. Herein, we developed a concise, rapid and ultrasensitive surface-enhanced Raman scattering (SERS) sensor for N₂H₄ detection based on alpha-cyclodextrin-silver nanoparticles (α-CD-AgNPs) modified by 4-mercaptobenzaldehyde (4-MBA). The 4-MBA molecules can specifically capture the N₂H₄ molecules and undergo a Schiff base reaction. As a result, this induces the aggregation of nanoparticles and generates a new characteristic peak at 1529 cm^–1 that is attributed to CN and CC vibrations. Compared with noble metal nanoparticles, 4-MBA not only formed AgS bonds but could also be fixed in the cavity of cyclodextrin to produce a more stable and stronger SERS signal. The SERS intensity at 1529 cm^–1 and the logarithm of the concentration of N₂H₄ presented a good linear relationship from 10^–9 to 10^–7 M with an unprecedented limit of detection (LOD) of 38 pM. The proposed SERS sensor exhibited satisfactory selectivity and reproducibility and was applied to detect N₂H₄ in real and complex water samples. We expect this assay to be a promising alternative tool for the on-site detection of N₂H₄.

由于该物质的高毒性，开发用于测定肼 (N ₂ H _{4 ) 的简便测定法已引起人们的极大关注。}在此，我们开发了一种基于 4-巯基苯甲醛 (4-MBA) 改性的 α-环糊精-银纳米粒子 (α-CD-AgNPs)的简洁、快速和超灵敏的表面增强拉曼散射 (SERS) 传感器，用于 N ₂ H ₄检测. 4-MBA分子可以特异性捕获N ₂ H ₄分子并进行席夫碱反应。结果，这会诱导纳米颗粒的聚集并在 1529 cm ^-1处产生一个新的特征峰，这归因于 C N 和 CC 振动。与贵金属纳米粒子相比，4-MBA不仅可以形成Ag S键，还可以固定在环糊精的空腔中，产生更稳定、更强的SERS信号。^{1529 cm –1}处的 SERS 强度和 N ₂ H ₄浓度的对数在10 ^–9到 10 ^–7 M之间呈现出良好的线性关系，具有前所未有的 38 pM 检测限 (LOD)。所提出的 SERS 传感器表现出令人满意的选择性和重现性，可用于检测真实和复杂水样中的 N ₂ H ₄。我们希望该测定法成为现场检测 N ₂ H的有前途的替代工具₄ .