Highly fluorogenictetrazinebioorthogonalprobes emitting at near‐infrared wavelengths are in strong demand for biomedical imaging applications. Herein, we have developed a strategy for forming a palette of novel Huaxi‐Fluor probes in situ, whose fluorescence increases hundreds of times upon forming the bioorthogonal reaction product, pyridazine. The resulting probes show large Stokes shifts and high
growing application of tetrazine bioorthogonal chemistry, it is still challenging to access tetrazines conveniently from easily available materials. Described here is the de novo formation of tetrazine from nitriles and hydrazine hydrate using a broad array of thiol‐containing catalysts, including peptides. Using this facile methodology, the syntheses of 14 unsymmetric tetrazines, containing a range of
aggregation-induced emission (AIE) characters and multicolor emissions after bioorthogonal reaction with strained dienophiles. Manipulating the π-bridge in the fluorophore skeleton allows fine-tuning of the emission wavelength and influences the AIE-active properties. With these probes, we succeeded in no-wash fluorogenic protein labeling and mitochondria-selective bioorthogonal imaging in livecells.
tetraphenylenes (TPEs) as bio-orthogonally activated aggregation-induced emission (AIE) fluorogenic probes. Both the fluorescence and AIE features are quenched by tetrazine, which is mediated by the through-bondenergy-transfer (TBET) mechanism, and are activated upon converting tetrazine to pyridazine via the inverse electron-demand Diels–Alder (iEDDA) reaction. The activated cycloadducts displayed a notable fluorescence