A novel fluorescent chemosensor based on naphthofuran functionalized naphthalimide for highly selective and sensitive detecting Hg2+ and CN-

To develop simple and low-cost method for efficiently detecting toxic ions such as Hg2+ and CN- is a vital challenge. In this work, a novel fluorescent sensor NF was successfully designed and synthesized by employing naphthofuran and naphthalimide groups as fluorescent signal groups as well as binding sites. Based on the collaboration of these two groups, the NF shows fluorescent response to Hg2+ with high sensitivity and specific selectivity, and the lowest of detection limit (LOD) of the NF for Hg2+ is 4.7 x 10(-7) M. Moreover, the complexes NF-Hg2+ can serve as fluorescence Turn-On selective sensor for CN-, the LOD for CN- is 5.58 x 10(-8) M. More importantly, the NF shows highly sensitivity and selectivity for Hg2+ and CN- with the high anti-interference ability. The ions recognition mechanisms of the NF for Hg2+ and NF-Hg2+ for CN- were carefully investigated by experiments and quantum chemical calculations including density functional theory (DFT), electrostatic surface potential and frontier molecular orbital theroy, which not only supplied deeply insight on the collaboration of the naphthofuran and naphthalimide groups, but also confirmed the charge transfer. In addition, the logic gate and test kits for fluorescent detection of Hg2+ and CN- were also prepared.

Automated summary

Developing a simple and low-cost method for detecting toxic ions is a crucial challenge. This study presents a novel fluorescent sensor that shows high sensitivity and specific selectivity towards Hg2+ and CN-. The sensor also functions as a fluorescence turn-on selective sensor for CN- with high anti-interference ability. The mechanisms of ion recognition were investigated through experiments and quantum chemical calculations, providing insights into the collaboration of the fluorescent signal groups and confirming charge transfer. Additionally, logic gates and test kits for detecting Hg2+ and CN- were prepared.