Boronate‐Based Fluorescence Probes for the Detection of Hydrogen Peroxide

In this work, we synthesized a series of boronate ester fluorescence probes (E)‐4,4,5,5‐tetramethyl‐2‐(4‐styrylphenyl)‐1,3,2‐dioxaborolane (STBPin), (E)‐N,N‐dimethyl‐4‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)styryl)aniline (DSTBPin), (E)‐4‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)styryl)benzonitrile (CSTBPin), (E)‐2‐(4‐(4‐methoxystyryl)phenyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane (MSTBPin), (E)‐N,N‐dimethyl‐4‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)styryl)naphthalen‐1‐amine (NDSTBPin), and N,N‐dimethyl‐4‐(2‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)phenyl)oxazol‐5‐yl)aniline (DAPOX‐BPin) for the detection of hydrogen peroxide (H(2)O(2)). DSTBPin and MSTBPin displayed an “Off–On” fluorescence response towards H(2)O(2), owing to the loss of the intramolecular charge transfer (ICT) excited state. Whereas, CSTBPin displayed a decrease in fluorescence intensity in the presence of H(2)O(2) owing to the introduction of an ICT excited state. STBPin, on the other hand, produced a small fluorescence decrease, indicating the importance of an electron‐withdrawing or electron‐donating group in these systems. Unfortunately, the longer wavelength probe, NDSTBPin, displayed a decrease in fluorescence intensity. Oxazole‐based probe DAPOX‐BPin produced a “turn‐on” response. Regrettably, DAPOX‐BPin required large concentrations of H(2)O(2) (>3 mm) to produce noticeable changes in fluorescence intensity and, therefore, no change in fluorescence was observed in the cell imaging experiments.