Real-Time Monitoring of Endogenous Peroxynitrite Levels in HepG2 Cells using SiQDs-(K/L-P)ox Probe

The study evaluated the effectiveness of endogenous peroxynitrite imaging in HepG2 cells using a novel SiQDs-(K/L-P)ox probe. As shown in Figure 5c, HepG2 cells displayed strong yellow fluorescence at 514 nm after 30 minutes of incubation with SiQDs-(K/L-P)ox. Upon stimulation with 10 μg/mL of LPS to induce ONOO- production, the yellow fluorescence intensity decreased, and the red fluorescence was almost completely quenched after 2 hours.

Control experiments using DMSO (300 μM) to inhibit endogenous ONOO- production before LPS treatment showed no change in yellow fluorescence intensity at 514 nm after 1 and 2 hours, confirming the observed fluorescence changes were due to ONOO- generation. The processed data in the Spec3 channel visually demonstrated the changes in fluorescence intensity of the SiQDs-(K/L-P)ox within HepG2 cells.

These findings suggest that the developed SiQDs-(K/L-P)ox probe can be utilized to monitor changes in endogenous ONOO- levels in living cancer cells in real-time. The study provides valuable insights into the effectiveness of endogenous peroxynitrite imaging in HepG2 cells, highlighting the potential of the SiQDs-(K/L-P)ox probe as a powerful tool for monitoring ONOO- dynamics in living cancer cells.