Aggregation‐induced emission‐active poly (β‐lactam) prepared by Staudinger polymerization as specific probe to Fe³⁺ ions and its antimicrobial properties

Abstract

For the nontraditional aggregation‐induced emission (AIE) active polymers, the heterocyclic structure on the macromolecular backbone and side chains play a crucial role in its fluorescence generation. In this paper, we facilely prepared a series of poly(β‐lactam) derivatives (PLTM) by Staudinger polymerization. As expected, PLTMs with four‐membered heterocycles along the main‐chain shows a remarkable AIE performance with the fluorescence emission at 520 nm, while no fluorescence was observed for both β‐lactam (repeating unit) and a model polymer for PLTM. The fluorescence properties of PLTMs greatly depend on the intramolecular aggregation of β‐lactam structures, the size of the substituents, and appropriate length of CH2 spacer. In addition, PLTMs can specifically detect Fe3+ ions with a limit of detection (LOD) of 7.2 μM even in the presence of other 13 metal ions. Similar to the biological activity of β‐lactam, AIE‐active PLTMs shows a bactericidal effect on Staphylococcus aureus and Escherichia coli with the minimum inhibitory concentration of about 8 and 4 mg/mL. In brief, the preparation and versatility of PLTMs with β‐lactam structure provide useful references for designing other nontraditional AIE‐active polymers as well as for ion detection and antibacterial processes.