An ESIPT-based ratiometric fluorescent probe for detecting H(2)O(2) in water environment and biosystems

The outbreak of the COVID-19 has resulted in a great increase in the use of H(2)O(2) disinfectant, which is listed as one of the commonly used disinfectants for COVID-19 by the U.S. Environmental Protection Agency. However, excessive use of H(2)O(2) disinfectant can threaten human health and damage the water environment. Therefore, it's of great importance to detect H(2)O(2) in aquatic environments and biological systems. Herein, we proposed a novel ESIPT ratio fluorescent probe (named probe 1) for detecting H(2)O(2) in water environment and biosystems. Probe 1 emits blue fluorescence as the introduction of the phenylboronic acid disrupts the ESIPT process. After reacting with H(2)O(2), the phenylboronic acid is oxidatively removed, and the ESIPT process is restored, which makes the fluorescence emission wavelength red-shifted. Probe 1 exhibited a short response time, high sensitivity, and a large Stokes shift to H(2)O(2). Importantly, it has been successfully used to detect H(2)O(2) not only in actual water samples, but also endogenous and exogenous H(2)O(2) in living cells. The characteristics of probe 1 have a wide range of applications in environmental and biological systems.