In this review, recent progress in tetrazine-based fluorogenic probes for bioorthogonal chemistry is comprehensively analyzed, with a focus on advancements in probe design and their imaging applications for molecular processes in live cells.
The luminogenic click reaction of 1,2,4-triazine-functionalised phenanthroline iridium(III) complexes opens easy pathways for luminescent bioconjugates.
Evaluation of tetrazine-modulated fluorogenic Cy3 probes revealed that internal conversion-based quenching of fluorescence results in better fluorogenic performances even in spectral ranges where tetrazines have diminished modulation power.
An iridium(III) 3-chloro-6-thio-1,2,4,5-tetrazine complex was modified with an RGD peptide, affording a photoactive conjugate that specifically targeted tumour cells and showed enhanced emission and singlet oxygen generation upon photoirradiation.
Click’n lock describes a reaction system capable of switching on-demand from reversible to irreversible click reactions and is based on the chemoselective tetrazine–thiol exchange. Here, click’n lock is applied for dynamic modifications of peptides.