Charge-driven tripod somersault on DNA for ratiometric fluorescence imaging of small molecules in the nucleus

Although fluorescence tracing of small bioactive molecules in living cells has been extensively studied, it is still a challenging task to detect their variations in the nucleus mainly due to the impermeable nuclear membrane and nucleic acid interference. Herein, we take advantage of the nucleic acid enriched environment in the nucleus to establish a strategy, named "charge-driven tripod somersault on DNA", for ratiometric fluorescence imaging of small bioactive molecules in the nucleus.