▎ 摘　　要

The detection of intact cells in their original state is of great importance for early diagnosis of disease. In this work, we report the detection of living K562 chronic myeloid leukemia cells using an innovative label-free hybrid graphene/gold nanopyramid based surface-enhanced Raman scattering (SERS) trough grid method. The position of the cells can be well controlled by the trough grid so that they can remain unchanged in the liquid at room temperature for up to 2 h. The graphene sheet permits SERS hot spot identification and provides a chemical enhancement for the biological constituents. Different states of K562 cells were thus detected. Two types of SERS signals of K562 cells can be clearly distinguished using principal component analysis (PCA), corresponding to two different states of the K562 cell, namely, the living state and dead state. And their SERS signal ratio severely varies as a function of the storage time. PCA analysis shows that, within 2 h after taking K562 cells out of the incubator, living cells account for more than 60% of the total cells. The SERS signal variation has been attributed to an increased number of dead cells suspended in the cell culture fluid. We demonstrate a proof-of-concept study of the clarification of the state variation, from the molecular level, of the K562 cells as a function of time using a graphene-SERS platform. This method is of great potential for leukemia diagnosis and on the development of leukemia drugs.