3D SERS (surface enhanced Raman scattering) imaging of intracellular pathways.

We demonstrate dynamic surface-enhanced Raman scattering (SERS) imaging with 3 dimensional mapping in a living cell by combining a confocal Raman spectrometer and dual-focus dark-field microscopy. Gold nanoparticles acting as a probe traveling through the living cell, are tracked by dual-focus dark-field imaging, with position feedback to the confocal Raman spectrometer in order to record evolving SERS signals from the same gold nanoparticle moving through the cell. Simultaneous detection of motion and the SERS spectrum enables the visualization of the SERS pathways. Observation of how the SERS spectra change in space and time during biological functions or by changes of the molecular environment provides exciting opportunities for understanding the molecular basis of the cell dynamics.