Construction of photofunctional peptide conjugates through selective modification of N-terminal cysteine with cyclometallated iridium(III) 2-formylphenylboronic acid complexes for organelle-specific imaging, enzyme activity sensing and photodynamic therapy.

Luminescent cyclometallated iridium(III) complexes bearing a 2-formylphenylboronic acid moiety were designed; one of the complexes was utilised to modify peptides containing an N-terminal cysteine to afford luminescent conjugates with selective organelle-targeting or furin-responsive properties.