Recognition of tumor cells by immuno-SERS-markers in a microfluidic chip at continuous flow.

SERS active nanoparticles were labeled with a reporter molecule and conjugated with anti-EpCAM antibodies. These immuno SERS markers were mixed with leukocytes, MCF-7 breast cancer cells and polystyrene beads, and the mixture was injected into a microfluidic quartz chip. Raman spectra were acquired at 785 nm excitation with 25 milliseconds exposure time in a continuous flow regime. Spectral unmixing by N-FINDR identified spectral signatures of SERS-labelled cells and polystyrene beads. This approach demonstrated rapid and reproducible SERS-assisted cell detection. Strategies are discussed to further increase the throughput for cell sorting.