A supramolecular self-assembly host-guest system from cyclodextrin as an absolute water-soluble fluorescence sensor for aluminium ions: Synthesis, characterization and sensing activity

Abstract

In the study, an organic molecule derived from paeonol and anthraniloyl hydrazine (L) was synthesized via a Schiff-base reaction. Moreover, a host-guest system composed of TEPA-β-CD and L was self-assembled via supramolecular interactions. The organic molecule and host-guest system were characterized via NMR, HRMS, IR, and SEM. In addition, the internal structure of the system was clearly observed via HRTEM. The host-guest system exhibited absolute water-solubility. Via the fluorescence behavior toward several metal ions in aqueous media without organic solvents (pH = 7.2), the host-guest system showed high selectivity toward Al3+ over other commonly coexistent metal ions. Therefore, this host-guest system can be used as a fluorescence sensor for aluminium ions in aqueous media. Moreover, a large binding constant (5.84 × 104 M-1) between the sensor and Al3+ was calculated via a fluorescent titration experiment. Additionally, the absolute water-solubility activity effectively enhanced the application value of the host-guest system for tracking and detection of Al3+.