erivative fl uorescent probe for cascade recognition of phosphate and iron ions in aqueous medium and its logic gate behavior †

A fluorescent probe based on benzimidazole was synthesized, and its cascade recognition of PO4 3 and Fe ions was investigated using spectroscopic techniques. This probe showed a highly sensitive and selective response towards PO4 3 and Fe relative to other anions and metal ions. Moreover, the resulting [probe–PO4 3 ] complex exhibited a turn-off response toward Fe ion, leading to the fabrication of an INHIBIT logic gate using PO4 3 and Fe ions as inputs and the emission of the probe as output. This research may enrich the field of multi-functional chemosensors in natural products.