Single gold@silver nanoprobes for real-time tracing the entire autophagy process at single-cell level.

This article describes a multimodified core-shell gold@silver nanoprobe for real-time monitoring the entire autophagy process at single-cell level. Autophagy is vital for understanding the mechanisms of human pathologies, developing novel drugs, and exploring approaches for autophagy controlling. A major challenge for autophagy study lies in real-time monitoring. One solution might come from real-time detection of in situ superoxide radicals (O2(•-)), because it is the main regulator of autophagy. In this work, our proposed nanoprobes were etched by O2(•-) and gave a notable wavelength change in the plasmon resonance scattering spectra. Both the experimental and simulated results suggested the wavelength change rate correlated well with O2(•-) level. This response enabled its application in real-time in situ quantification of O2(•-) during autophagy course. More importantly, with the introduction of "relay probe" operation, two types of O2(•-)-regulating autophagy processes were successfully traced from the beginning to the end, and the possible mechanism was also proposed.