A fluorescent probe based on Ir(III) solvent complex for specific recognition of histidine in aqueous solution and the application in cell imaging

Abstract

To develop novel fluorescent probes for detecting endogenous histidine (His) plays significant roles in physiological and pathological fields. Herein, a non-emissive Ir(III) complex [Ir(C–N)2(CH3CN)2]+NO3− (IrCN, C–N represents 2-phenylpyridine derivative) has been demonstrated to be a reaction-based fluorescent probe for the recognition of His in HEPES buffer. It is found that IrCN can selectively detect His with a distinct “turn-on” luminescence and low limitofdetection (LOD = 0.62 μM), relying on which, IrCN can light-up the cytoplasm and nuclear region of the fixed cells, exhibiting negligible cytotoxicity and suitable solubility under test concentration.