Interference-Free Surface-Enhanced Raman Scattering Tags for Single-Cell Molecular Imaging with a High Signal-to-Background Ratio.

An interference-free surface-enhanced Raman scattering tag is constructed to profile the expression of cancer biomarkers at the single-cell level. The Raman tags present a strong and sharp peak in the cellular Raman-silent region, significantly diminishing the background interference. Moreover, the reporters are embedded in the layered gold nanoparticles, avoiding desorption and enzymatic degradation in physiological conditions.