Phosphate‐Modulated Aggregation‐Induced Electrochemiluminescent Zr‐MOF for Ultrasensitive Bacterial Detection
Zirui Wang, Junhan Li, Shujia Wang, Zhida Gao, Yan‐Yan Song
Abstract
Abstract Bacterial infections pose a growing public health risk, necessitating rapid, sensitive, and reliable detection methods. Herein, a novel aggregation‐induced electrochemiluminescence (AIECL) platform is developed, based on a three‐ligand zirconium metal‐organic framework (Zr‐MOF), for ultra‐rapid and trace‐level bacterial sensing through phosphate‐triggered signal modulation. The framework integrates tetraphenylethylene (TPE)‐derived AIE ligands with two types of ancillary ligands, endowing the material with both structural rigidity and abundant rotational sites. When ions enter the MOF pores, they restrict the rotation/vibration of the pendant phenyl rings in the TPE units, resulting in a pronounced “turn‐on” ECL signal and enhanced sensitivity. Upon exposure to phosphate ions released by bacterial alkaline phosphatase activity, the monodentate ligands are selectively displaced, leading to ECL quenching. Structural characterization confirms that the three‐ligand architecture retains high crystallinity and porosity, while ECL measurements demonstrate a significant enhancement in ECL intensity compared with traditional MOFs. Crucially, this phosphate‐responsive AIECL sensor achieves single‐bacteria‐level detection within 17 min in complex biological media, demonstrating excellent selectivity over common interfering ions and microbial species. The straightforward phosphate‐trigger mechanism, coupled with the robustness of the Zr‐MOF scaffold and the inherent advantages of AIECL readout, makes this system a powerful tool for fast, point‐of‐care bacterial diagnostics.