Synthesis and Characterization of a Novel ELF-97-based Fluorescent Probe for Hydrogen Peroxide Detection

A novel 2-(2′-hydroxy-5′-chlorophenyl)-6-chloro-4(3H)-quinazolinone (ELF-97)-based fluorescent probe (P1) for H2O2 analysis was prepared with 5-chlorosalicylaldehyde, 4-(bromomethyl)phenylboronic acid and 2-amino-5-chlorobenzamide as the materials, and its structure was characterized by 1H nuclear magnetic resonance (NMR), 13C NMR and high resolution mass spectrometry (HRMS). Weak fluorescence intensity was observed at 425 nm when the solution of probe P1 was excited by 360 nm UV light. After addition of H2O2, however, the emission peak at 425 nm disappeared while a strong emission peak at 515 nm appeared with the same excitation wavelength (360 nm). The fluorescence intensity at 515 nm is dependent on the concentration of H2O2, with the linear response range of 5–45 μM. The detection limit and the recovery of H2O2 in milk sample were 0.1 μM and 94.0%–106.0%, respectively. The results show that probe P1 is potential to become a useful tool for rapid detection of H2O2.

Graphical abstractA highly selective turn-on fluorescent probe with large Stoks shift, for rapid detection of H2O2 was developed based on the protection-deprotection of 2-(2′-hydroxy-5′-chlorophenyl)-6-chloro-4(3H)-quinazolinone (ELF-97). The fluorescence intensity at 515 nm is dependent on the concentration of H2O2, with the linear response range of 5–45 μM.Figure optionsDownload full-size imageDownload as PowerPoint slide