Dynamic Detection of Endogenous Hydroxyl Radicals at Single-Cell Level with Individual Ag-Au Nanocages

摘要

Hydroxyl radicals (center dot OH) are a type of short-lived radical which is the most aggressive reactive oxygen species due to its high reactivity to biomolecules. Dynamic measurement of center dot OH level in living cells is critical for understanding cell physiology and pathology. In this manuscript, we prepare individual Ag-AupPEG/RGD nanocages for in situ determination of endogenous center dot OH at single-cell level, whose spectral shift rate correlate to the center dot OH concentration. The high-selective response to center dot OH relies on the specific oxidization of the conjugated PEG/RGD outside and the silver etching inside the nanocages that resulted in a significant LSPR signal and scattered color changes. The spectral red-shift rate of LSPR has a linear relationship with the logarithm of center dot OH concentration in range of 100 pM to 1 mu M, suitable for the measurement of endogenous center dot OH. Thus, the individual nanocages were successfully used to monitor the dynamic intracellular center dot OH level of single tumor cells under oxidative stress. This strategy has great potential in promoting center dot OH mediated cell homeostasis and injury research.