The present application relates to photostabilized or self-healing dyes that are constructed by attaching an azoaryl unit to a parent dye such that its optical properties are improved, particularly its optical properties that are most relevant in highly-demanding imaging, including instant brightness, signal stability, photon budget, and rate of detecting localisations. Therefore the compounds of the invention can be useful for high-performance imaging, e.g. delivering higher spatial and temporal resolution, within a shorter experimental acquisition time, and with more confidence, whether in oxygen-free conditions or in aerated conditions.

The present application relates to photostabilized or self-healing dyes that are constructed by attaching an azoaryl unit to a parent dye such that its optical properties are improved, particularly its optical properties that are most relevant in highly-demanding imaging, including instant brightness, signal stability, photon budget, and rate of detecting localisations. Therefore the compounds of the invention can be useful for high-performance imaging, e.g. delivering higher spatial and temporal resolution, within a shorter experimental acquisition time, and with more confidence, whether in oxygen-free conditions or in aerated conditions.