A diketopyrrolopyrrole-based hybrid organic nanoprobe for ratiometric imaging of endogenous hypochlorite in live cells

Abstract Using the fluorescence resonance energy transfer (FRET) and the aggregation-induced emission (AIE) strategies, we herein develop an organic micellar nanoprobe by the co-assembly of phenyl-diketopyrrolopyrrole (PDPP1) and amphiphilic tetraphenylethene (TPE1) in aqueous solution for ratiometic detection of hypochlorite. PDPP1, the energy acceptor in this FRET nanosystem, holds high chemical activity and responds rapidly, selectively and sensitively to hypochlorite with the C = C double bond in DPP core as the reactive site. On the other side, the skillful introduction of TPE1 not only inhibits the ACQ effect of PDPP1, but also helps to maintain the stable nanostructure of nanoprobe. At the presence of hypochlorite, C = C bonds in DPP core are oxidized and the FRET process between PDPP1/TPE1 is broken. These PDPP1/TPE1 nanoparticles respond rapidly to hypochlorite with good sensitivity/selectivity (the LOD, 32 nM) in the ratiometic way and are capable for imaging of exogenous and endogenous hypochlorite in live cells. Our research offers new insight into the simple construction of ratiometric nanoprobe for biological analyst with some smart organic fluorophores.