Cancer Cell Detection on the Surface of Top-Gated Monolayer Graphene via Raman Spectroscopy

A label-free biosensor is described based on the Raman spectroscopic signatures of monolayer graphene, which are modified in the compartment of cancer cells because of electron-phonon coupling in monolayer graphene. Specifically, the Raman spectra of electrostatically gated monolayer graphene on SiO2/Si substrates, in the voltage range from 0 to 5 V, were studied in the absence and the presence of cancer cells. Density functional theory simulations afforded a correlation between cancer cells and the observed Raman spectra, through the regulation of the intensities of the G and 2D Raman vibrational modes with applied voltage. The C-H and N-H bonds of phenylalanine enabled the detection of this biosensing activity. Significantly, this detection can be carried out even in the absence of cancer cell-culturing steps.

Automated summary

This study introduces a label-free biosensor based on monolayer graphene, which exploits the electron-phonon coupling to modify the Raman spectroscopic signatures within cancer cell compartments. Density functional theory simulations reveal a correlation between cancer cells and the observed Raman spectra, showing that cancer cells can be detected by controlling the intensities of the G and 2D Raman vibrational modes with applied voltage. The detection of phenylalanine bonds enables biosensing activity even without the need for cancer cell-culturing steps.