Two-photon (TP) microscopy has advantages for biological imaging in that it allows deeper tissue-penetration and excellent resolution compared with one-photon (OP) microscopy.

The whole molecule of the title compound, C15H14N2S, is approximately planar, with an r.m.s. deviation of 0.0382 Å from the best-fit mean plane through all 18 non-H atoms. In the crystal, dimers form through π–π stacking interactions between the benzene rings of adjacent benzothiazole ring systems, with a centroid–centroid separation of 3.6834 (16) Å.