Fabrication of a Multifunctional Fluorescent Supramolecular Assembly via Cucurbituril-Based Host–Guest Interactions in Aqueous Solution

The development of multifunctional materials is essential in advancing sustainable technologies. Here, a fluorescent supramolecular assembly (BPPy/Q[8]) has been fabricated via host–guest complexation with cucurbit[8]uril (Q[8]). This system utilizes dynamic noncovalent cross-linking to enable selective picric acid (PA) detection, and integrates a light-harvesting function with cellular imaging. The BPPy molecule self-assembles into nanosheet layers with Q[8] via π–π stacking and hydrogen bonding, exhibiting improved optical properties. The supramolecular assembly enables a selective and highly sensitive detection of PA, with a detection limit of 5.58 × 10 –7 mol·L –1 . A water-phase artificial light-harvesting system was developed by incorporating anionic rhodamine B (A-RhB) via electrostatic interactions, delivering an energy transfer efficiency of 71.8%. Cellular experiments have confirmed that A-RhB@BPPy/Q[8] produced intracellular red fluorescence, and exhibited low cytotoxicity (cell viability >90%), demonstrating good biocompatibility with HK2 cells. This study offers a strategy for applying cucurbit[ n ]uril-based supramolecular materials in environmental monitoring and biomedicine.