In the study, a highly selective and sensitive fluorescence sensor derived from nitrogen heterocycle was synthesized and characterized. By the fluorescence experiments, it was found to show a higher response toward Al³⁺ than other commonly coexistent metal ions in C₂H₅OH/H₂O media (pH = 7.2). Moreover, the large binding constant (3.44 × 10¹⁴ M⁻¹) between Al³⁺ and the sensor was calculated by fluorescence titration experiment. In addition, the synergistic effect mechanism due to photoinduced electron transfer (PET) and CN isomerization was deduced according to the fluorescence behavior. In addition, the fluorescence imaging in living cells was studied systemically, which exhibited high fluorescence sensing activity toward Al³⁺.

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⁺.

Multicolor fluorescence N-doped CPDs from dextrin water solution in strong acidic and alkaline environments were synthesized and characterized, which revealed that pH value plays a vital role in the process of CPD growth.

In this work, we present an excellent water-soluble supramolecular self-assembled fluorescent nanosensor toward Al³⁺based on graphene oxide and a β-cyclodextrin derivative.