Turn-on Luminescent Probe for Hydrogen Peroxide Sensing and Imaging in Living Cells based on an Iridium(III)...

A sensitive turn-on luminescent sensor for H₂O₂ based on the silver nanoparticle (AgNP)-mediated quenching of an luminescent Ir(III) complex (Ir-1) has been designed. In the absence of H₂O₂, the luminescence intensity of Ir-1 can be quenched by AgNPs via non-radiative energy transfer. However, H₂O₂ can oxidize AgNPs to soluble Ag⁺ cations, which restores the luminescence of Ir-1. The sensing platform displayed a sensitive response to H₂O₂ in the range of 0-17 μM, with a detection limit of 0.3 μM. Importantly, the probe was successfully applied to monitor intracellular H₂O₂ in living cells, and it also showed high selectivity for H₂O₂ over other interfering substances.