LAUSR

Taking the advantages of excellent optical property, bio-compatibility and photostability of carbon dots, herein, we developed a polarity-sensitive polymer carbon dots (PCDs) for visualizing of cellular polarity to real-time monitoring autophagy changes without perturbing the cellular status. The PCDs can be prepared by simply mixing dopamine (DA), H2O2 and o-phenylenediamine (o-PDA) in a common beaker without the need for any special equipment or external energy supply, and the preparation could be completed within three minutes at room-temperature. Interestingly, the polarity-sensitive PCDs could emit various fluorescence and insensitive of the excitation light when dispersed in different water/dioxane systems with different polarities. Based on the polarity-sensitive emission of the PCDs, the change of polarity during autophagy has been successfully monitored in living cells. Moreover, the change of polarity detected by PCDs is autophagy-specific (does not occur during apoptosis), occurs under different autophagy-inducing situations (starvation, rapamycin and trehalose), and requires normal autophagic flux, showing that PCDs rapidly prepared by polymerization crosslinking at room temperature can be functionally applied in the case of autophagy-related physiological or pathological processes.