Rapid and Visual Detection of Al3+ Based on Supramolecular Self-Assembly of a Water-Soluble Perylene Diimide Derivative

Aluminum (Al) is widely used in food industry, but excessive absorption of Al3+ causes many serious health problems. Therefore, it is of great significance to determine the specificity of Al3+. In this study, we designed and synthesized a water-soluble perylene diimide derivative (PDI-Phe) for monitoring Al3+ rapidly and visually. Through absorption and emission spectroscopy techniques, we systematically explored the properties and mechanism of the sensor to Al3+. The limit of detection (LOD) of Al3+ was as low as 6.54 nM. And with the existence of Al3+, electrostatic interaction and intermolecular pi-pi stacking promoted the aggregation and fluorescence quenching of PDI-Phe. Even in the presence of other analytes, PDI-Phe still had excellent selectivity and sensitivity for Al3+ detection. Besides, it also had the characteristics of low cost, good water solubility, excellent chemical and optical stability, and easy synthesis. Finally, this method can be further applied to tap water samples.