A red-emitting styrylnaphthalimide-based fluorescent probe providing a ratiometric signal change for the precise and quantitative detection of H2O2.

A red-emitting and ratiometric fluorescence probe 1 for detecting H 2 O 2 , based on a styrylnaphthalimide-boronate ester was developed. Upon a H 2 O 2 -mediated hydrolysis of boronate ester, probe 1 was transformed to 2 with a ratiometric fluorescence change, decrease at 535 and increase at 640 nm. It was also found that the fluorescent reaction of 1 with H 2 O 2 in solution could be completed within 10 min and the detection limit was estimated to be 0.30 μM. Moreover, this ratiometric change was highly selective for H 2 O 2 over other redox species, metal ions, and anions. Also, this system was found to be capable of detecting H 2 O 2 in the pH range of 6–9. Furthermore, probe 1 was preferentially accumulated into the endoplasmic reticulum (ER) in the live HeLa cells, and an increased H 2 O 2 level in the presence of an ER stress inducer, thapsigargin was revealed. Image 1 • A red-emitting and ratiometric fluorescence probe for detecting H 2 O 2 was developed. • This probe is based on H 2 O 2 -mediated hydrolysis of styrylnaphthalimide-boronate ester. • This probe can show a selective fluorescence change between 535 and 640 nm to H 2 O 2. • The probe can detect H 2 O 2 within 10 min with the detection limit of 0.30 μM. • This probe can be utilized to monitor H 2 O 2 in the ER of the live cells. [ABSTRACT FROM AUTHOR]