A G-triplex luminescent switch-on probe for the detection of mung bean nuclease activity

A cyclometallated Ir(iii) complex was synthesised and evaluated for the ability to act as a luminescent G-triplex probe. The iridium(iii) complex 1 [Ir(phq)₂(2,9-dmphen)]PF₆ (where phq = 2-phenylquinoline; 2,9-dmphen = 2,9-dimethyl-1,10-phenanthroline) exhibited high luminescence for G-triplex DNA over dsDNA and ssDNA, and was employed to construct a label-free G-triplex-based assay for mung bean nuclease activity in aqueous solution. This method was highly sensitive and selective for MB nuclease activity over other DNA-modifying enzymes.