A new intramolecular proton transfer (ESIPT)‐based fluorescent probe for selective visualization of cyanide ion
Cui‐Bing Bai, Jie Zhang, Wen Ma, Junxiong Yao, Qian Meng, Zhenni Xia, Dashuo Chen, Shuping He, Lin Zhang, Changqing Qu, Rui Qiao, Zhèn Yáng, Wei Huang
Abstract
Abstract Fluorescent probes for detection of CN − still have many limitations, such as small Stokes shift, irreversible, and background interference, which hamper their applications for on‐site detection and bioimaging of CN − . In this work, we design a new CN − ‐activatable fluorescent probe (named AHMM) containing an ESIPT (excited‐state intramolecular proton transfer) and hydrogen bond features, which show a large Stokes shift (225 nm) and molecular structural reversible detection. The probe AHMM exhibits an excellent selectivity for CN − without any interference from other anions in aqueous DMSO system. Furthermore, the mechanism of the interaction of AHMM with CN − is concluded by various experiments. The limit of detection of AHMM for CN − is calculated as low as 4.47 × 10 −8 M, lower than the concentration of CN − deemed acceptable by WHO (World Health Organization). AHMM can recognize CN − in tap water quantitatively and on‐site by a smartphone APP. Moreover, food samples such as almond and cassava including CN − are visualized by fluorescence imaging. In addition, the probe shows practical applications of CN − imaging in cells and mice. This concept can be applied for designing multifunctional fluorescent probes with ESIPT and reversible characteristics for detection of CN − .