Recent advances in small-molecule fluorescent probes bearing a triaminoguanidinium unit and their sensing, bio-imaging and multifunctional applications.

Since their discovery, triaminoguanidinium-salicylidene-based Schiff bases have emerged as a significant class of compounds known for their solvent-dependent fluorescence emission, which varies depending on the substituents in their aromatic frameworks. These compounds are easy to synthesize, stable, cost-effective, and highly suitable for diverse applications, including chemosensing, biological studies, and multifunctional uses. This comprehensive review summarizes recent advancements in AIE-active triaminoguanidinium-salicylidene-based threefold symmetric Schiff molecules, particularly their role as chemosensors for detecting various analytes. It explores different chemosensing strategies for identifying metal ions (Zn, Cd, Cu, Fe, and Co) and anions (EDTA, I PPi, and S), focusing on the progress of triaminoguanidinium-salicylidene-based threefold symmetric Schiff bases over the past five years, particularly their systems for supramolecular host-guest interactions, AIEgen-ESIPT activity, COFs, bioimaging, . We hope this review provides a comprehensive overview of the current research landscape and encourages further exploration of novel triaminoguanidinium-salicylidene-based threefold symmetric Schiff base compounds with expanded applications.