Li Hongda, Chen Tie, Jin Longyi, Kan Yuhe, Yin Bingzhu
Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules of the Ministry of Education, Department of Chemistry, Yanbian University, Yanji 133002, PR China; Department of Forensic Chemistry, National Police University of China, Shenyang 110854, PR China.
Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules of the Ministry of Education, Department of Chemistry, Yanbian University, Yanji 133002, PR China.
Anal Chim Acta. 2014 Dec 10;852:203-11. doi: 10.1016/j.aca.2014.09.018. Epub 2014 Sep 18.
In this study, we synthesized CTB and CB probes based on doubly activated Michael acceptors to selectively detect cyanide (CN(-)) anions through a one-step condensation reaction of coumarinyl acrylaldehyde with the corresponding derivatives of malonyl urea (thiourea). Through the conjugated addition of CN(-) to the β-site of the Michael acceptor, both probes displayed colorimetric and fluorometric dual-modal responses that were highly reactive and selective. CTB generates an active fluorescent response, whereas CB displays a ratiometric fluorescent response. The fluorescent signal of the probes reached its maximum given only 1 CN(-) equivalent and the signal change was linearly proportional to CN(-) concentrations ranging from 0 to 5 μM with the detection limits 18 and 23 nM, respectively. The reaction rate of the probes is highly dependent on the methylene acidity of malonyl urea derivatives. Thus, the response rate of CTB to CN(-) is 1.2-fold faster than that of CB, and the response rate of CB to CN(-) is 1.2-fold faster than that of the previously examined CM. We then verified the highly reactive nature of the β-site of the probes through density functional reactivity theory calculations. In addition, according to proof-of-concept experiments, these probes may be applied to analyze CN(-) contaminated water and biomimetic samples. Finally, cell cytotoxicity and bioimaging studies revealed that the probes were cell-permeable and could be used to detect CN(-) with low cytotoxicity.
在本研究中，我们基于双活化迈克尔受体合成了CTB和CB探针，通过香豆素基丙烯醛与丙二酰脲（硫脲）的相应衍生物的一步缩合反应来选择性检测氰化物（CN(-)）阴离子。通过CN(-)对迈克尔受体β位的共轭加成，两种探针均表现出比色和荧光双模态响应，具有高反应活性和选择性。CTB产生活性荧光响应，而CB表现出比率荧光响应。仅加入1当量的CN(-)时，探针的荧光信号就达到最大值，并且信号变化与0至5μM的CN(-)浓度呈线性比例，检测限分别为18和23 nM。探针的反应速率高度依赖于丙二酰脲衍生物的亚甲基酸度。因此，CTB对CN(-)的响应速率比CB快1.2倍，CB对CN(-)的响应速率比之前研究的CM快1.2倍。然后，我们通过密度泛函反应性理论计算验证了探针β位的高反应活性。此外，根据概念验证实验，这些探针可用于分析受CN(-)污染的水和仿生样品。最后，细胞毒性和生物成像研究表明，这些探针具有细胞渗透性，可用于检测CN(-)，且细胞毒性较低。
