We hypothesised that nitrogen in the ring would encourage better planarity and conjugation compared to sulfur, which in turn would enhance the fluorescence properties by imparting a better push-pull nature to the fluorophore. Herein, we report the synthesis of four 2F-2CN-Cys and 2F-2CN-(β-NH2Ala) analogues appended to maleimide and suitable for conjugation to proteins through the thiol-ene click reaction, assess their photophysical properties, and demonstrate the application of these fluorophores in the bioimaging of actin filaments and zebrafish embryos. Initially we synthesised 2F-2CN-Cys (1) and incorporated a maleimide functional group in three synthetic steps (Scheme 1a). First, we coupled carboxylic acid 1 with Boc-protected amine 2. After further deprotection, we incorporated maleimide to obtain fluorophore F1, for which we were able to obtain a crystal structure. The presence of the maleimide unit in the SBBF allows for site-specific thiol-ene click coupling with proteins through thiol-containing amino acids. The β-alanine analogue F2 was synthesised following a similar strategy (Scheme 1b). We prepared the carboxylic acid containing derivative (±)-5 by treating 4F-2CN (3) with 1,2-diaminopropionate (±)-4 followed by saponification. Following the same strategy as for F1, the maleimide group was attached to (±)-5 to obtain clickable precursor F2. As discussed above, we anticipated that the change of sulfur to nitrogen in F2 would offer better planarity and conjugation, which in turn should reflect in a better quantum efficiency of the fluorophore.