Mitochondria-targeting two-photon fluorescent probe for sequential recognition of Cu2+ and ATP in neurons and zebrafish.

Highly active mitochondria play a significant role in neuron function. Cu2+ and ATP levels in mitochondria regulate neuronal mitochondrial activity. However, mitochondrial activity was often evaluated by mitochondrial membrane potential. Less is known about the dynamics of Cu2+ and ATP in mitochondria. Herein, we developed a two-photon fluorescence probe (MP), which provided a determination of mitochondrial ATP and Cu2+. The fluorescence of MP showed remarkable quenching in the presence of Cu2+ and then gradually recovered in the presence of ATP, which can be used for sequential recognition. MP has high sensitivity to Cu2+ and ATP, with limits of detection (LOD) close to 0.31 nM and 13.6 nM, respectively. Using this useful probe, we monitor the fluctuation of concentrations of Cu2+ and ATP by fluorescence imaging at single neuron and zebrafish.