A mitochondrion-targeting fluorescent probe for hypochlorite anion in living cells

As momentous reactive oxygen species (ROS), it is necessary to develop high-sensitivity and high-specificity fluorescent probes for tracking hypochlorite anion (ClO^-) in environmental and biological systems. Herein, a kind of red luminescent carbon dots (NS-dots) was synthesized by one-step solvothermal method to detect ClO^- in PBS buffer solution (V_PBS:V_EtOH = 100:1, pH = 7.4). The NS-dots has high sensitivity and low detection limit (13.3 μmol/L) for detecting ClO^- with linear range from 6.7 × 10^-5 mol/L to 26.7 × 10^-5 mol/L. Using Rhodamine B (31% at 520 nm in water) as a reference, the NS-dots have a fluorescence quantum yield of 7.2%. Intracellular photostability, mitochondrial targeting properties and the fluorescence imaging towards intracellular ClO^- were demonstrated.