A facile ratiometric sensing platform based on inner filter effect for hypochlorous acid detection

[Display omitted] •The IFE-based ratiometric SP for HOCl detection was proposed for the first time.•The SP featured with weak cross-talk between the emission bands in HOCl detection.•The SP can be used for HOCl detection in 100% aqueous solution and live cell imaging.•The construction and application of SP demonstrates excellent flexibility and convenience. The easily constructed fluorescent probes with excellent sensing performance have attracted increasing attention in recent years. In this work, by virtue of the contrasting light absorption properties of neutral red (NR) and its product NR-NO after the reaction with hypochlorous acid (HOCl) for the fluorescence released from 4-triphenylvinyl-biphenyl (TPEP)-based nanoparticles (T-NPs), a facile inner filter effect (IFE)-based ratiometric sensing platform (SP) was constructed. Upon the addition of HOCl, a typical ratiometric fluorescence change and weak cross-talk between the emission bands (128 nm ≤ Δλem ≤ 182 nm) can be observed from SP, which effectively avoids the spectral overlap and ensures the high sensitivity (LOD = 62 nM) and accuracy in HOCl detection. In addition, because of the good water dispersibility and solubility featured in T-NPs and NR respectively, the SP can also be successfully applied to HOCl detection in 100% aqueous solution and live cell imaging. Moreover, the ratiometric SP avoids the complex covalent linking between fluorophore and energy acceptor, thereby providing great flexibility and convenience for its construction and application.