Etchable SERS Nanosensor for Accurate pH and Hydrogen Peroxide Sensing in Living Cells

No methodology has been built to distinguish the intracellular SERS nanosensors from the cell outer membrane bound-ones. Here we propose a “turning off” strategy by combining etchable SERS nanosensors with a non-permeable etchant. The SERS signals outside the living cells can be rapidly removed, leaving only the internalized nanosensors for imaging and thereby allowing accurate intracellular pH and H2O2 sensing.