Facile construction of AIE-based FRET nanoprobe for ratiometric imaging of hypochlorite in live cells

Abstract

Fluorescence resonance energy transfer (FRET) nanoprobes based on aggregated induced emission (AIE) molecules are promising for the monitoring of biomolecules in living cells, but this nanoprobe for reactive oxygen species (ROS) has rarely been reported. Here, a novel AIE-based FRET nanoparticles (NPs) is developed for ratiometric detection and imaging of hypochlorite in live cells. Different to common FRET-based nanosensors, the NPs is prepared via facile co-assembly strategy in water using amphiphilic tetraphenylethene (TPE1, energy donor) and thienyl-diketopyrrolopyrrole (NDPP, energy acceptor). This hybrid NPs are uniform spherical, with size of approximately 120 nm. NDPP maintains bright fluorescence inside the hybrid NPs and acts as the reactive unit for hypochlorite in this FRET nanosystem. As a ratiometric fluorescent nanoprobe, the hybrid NPs shows high selectivity to hypochlorite with a detection limit calculated to be 105 nM, thanks to its stable particle size in hypochlorite sensing. Furthermore, the successful ratiometric fluorescent imaging of ClO− in HeLa cells demonstrates that our NPs can effectively pass through the cell membrane and recognize the ClO− in living cells.