Quenching of Salicylaldehyde-based Luminescence Probe via Dakin Reaction: Approach for Highly Selective Detection of Hydrogen Peroxide

A novel assay for H 2 O 2 based on luminescence quenching is developed from the Dakin reaction between deprotonated salicylaldehyde (D-SA) and H 2 O 2 . Under alkaline condition, the phenolic hydroxyl group of SA is deprotonated, exhibiting good luminescence emission ability ( λ ex = 433 nm, λ em = 508 nm). Luminescence of D-SA is quenched by H 2 O 2 in a concentration-dependent manner. Good linearity is obtained with a regression coefficient of 0.9989 in the range of 0.3 ~ 150 μM and a detection limit (LOD) is 30 nM. In addition, D-SA luminescence probe shows good biocompatibility and low cytotoxicity to HeLa cells through MTT assay. The feasibility for in vitro applications is demonstrated through confocal laser scanning microscopy.