Functionalized DNA mimic of GFP based on the molecule-activated chromophore derivative for hydrogen peroxide detection

Hydrogen peroxide (H₂O₂) plays a pivotal role in both physiological and pathological processes, which attracted considerable attention to its content analysis. Detection of certain small molecules based on DNA/RNA mimics of green fluorescent protein (GFP mimics) has been preferentially constructed due to its high specificity, excellent optical properties, and high stability. However, there is a dearth of functional GFP mimics that can be directly activated by these targets. Herein, an H₂O₂-activated DNA mimic of GFP (HDG) has been proposed through primarily remolding the GFP chromophore derivative named 3,5-difluoro-4-hydroxybenzylidene imidazolidinone (DFHBI) with phenyl boronate group (PB-DFHBI) and then forming the HDG by adding the truncated Lettuce DNA aptamer (tLet-10) to reveal the specifically fluorescent response toward H₂O₂. In this sensing method, the fluorescence of PB-DFHBI is markedly declined with PB group lock by restricting its intramolecular charge transfer (ICT) process, while the presence of H₂O₂ will activate a cascade reaction to remove the PB group in HDG, resulting in a high-contrast and turn-on fluorescence. The unique emitting mechanism triggered by H₂O₂ endows HDG with stable, rapid response, high sensitivity, and specific detection performances, exhibiting a low detection limit of 0.59 μM and a comprehensive linear range of 1–1000 μM. Moreover, HDG was allowed to realize the reliable and accurate analysis of spiked H₂O₂ in beverage and water samples. It is believed that the well-designed HDG will provide a promising way to establish new sensing strategies for certain target analyses and expand their applications of GFP mimics-based sensing platforms.