A portable sensing platform using a novel dipyrrolopyrazinedione-based aza-BODIPY dimer for highly efficient detection of hypochlorite and hydrazine.

As widely used chemical reagents in different industrial fields, reactive hydrazine (NH) and hypochlorite (ClO) show significant risks to human health, drink water, and environment. Currently, fluorescence detection of two analytes suffers from slow and minor spectral change, high detection limit and poor selectivity. In this work, by introducing electron deficient 1,4-pyrazine ring enhanced chromophore reaction strategy, a novel dipyrrolopyrazinedione-based aza-BODIPY dimer (PzDP-PPAB) was synthesized for the first time. Interestingly, PzDP-PPAB for dual-responsive detection of NH and ClO has been developed, accompanying with large spectral change (Δλ = 250 nm for NH and Δλ = 277 nm for ClO), distinctly dual colorimetric/fluorescent turn-on responses, low detection limits (NH: 40 nM; ClO: 59 nM) and good selectivity. The sensing mechanism reveals that PzDP-PPAB chromophore as a novel recognition site is selectively disrupted by NH and ClO, where two different less conjugated products with diverse outputs were displayed. More importantly, PzDP-PPAB has been effectively utilized for detecting ClO in both water and vegetables samples with excellent recovery rate. The portable sensing platforms based on silica gel or sponge loaded with PzDP-PPAB provide a visual and convenient method for monitoring NH in both solution and gaseous state. This work presents a promising fluorescent probe for monitoring NH and ClO with a novel sensing mechanism capable of efficient detection of two pollutants.