Fluorescence imaging of glutathione with aptasensor and monitoring deoxynivalenol-induced oxidative stress in living cells

Glutathione (GSH) is an important intracellular antioxidant. It is closely related to the homeostasis of the intracellular redox state which can be changed through deoxynivalenol (DON) exposure. More importantly, GSH deficiency can directly lead to apoptosis and cellular metabolic disorders mediated by intracellular redox homeostasis. Therefore, real-time monitoring of dynamic changes of GSH levels in living cells is urgently needed for the evaluation of intracellular oxidative stress. Herein, for the first time, an aptamer-based recognition composite nanoprobe (Apt-AuNCs-MoS₂) was successfully constructed. The nanoprobe was employed for real-time and in situ imaging of DON-induced intracellular GSH changes and evaluation of oxidative stress status. The results indicated that the aptasensor revealed excellent specificity and high sensitivity to GSH in the solution system, and the limit of detection was as low as 35 nM. The results about DON-mediated oxidative stress indicated that the oxidative stress in living cells tends to be saturated with more than 20 ppm DON concentration. Thus, the strategy provides a novel aptasensor for the determination of GSH, offers a promising platform for fluorescence imaging of intracellular GSH in living cells, and further enriches in situ analysis of the in vitro toxicology.