▎ 摘　　要

In this article, we demonstrate the use of bioconjugated 2D graphene oxide (bio-GO) nanostructure to probe breast cancer cell (SKBR3) with excellent discrimination over other types of circulating tumor cell. We distinctly observed that bio-GO nanostructure targets and binds SKBR3 cell selectively in the cell mixture. Longer incubation of SKBR3 cellwith bio-GO causes Raman signal `turn off' when excited with 532-nm laser. This is attributed to penetration of the bio-GO through the plasma membrane of the cell by generating transient hole. Extraction of GO after cell digestion also supports the internalization rubric of 2D graphene through cell membrane. Our experimental data with the HaCaT healthy cell line, as well as with LNCaP prostate cancer cell line, clearly demonstrated that this Raman scattering assay is highly selective to SKBR3. The mechanism of selectivity and the assay's response change have been verified and discussed by utilizing fluorescence properties of GO and various other techniques. The experimental results open up a possibility of new label-free Raman scattering assay, for reliable diagnosis of cancer cell lines by monitoring 'turn-off' of the Raman signal from bio-GO nanostructure. Copyright (C) 2017 John Wiley & Sons, Ltd.