A graphene-based chemical nose/tongue approach for the identification of normal, cancerous and circulating tumor cells

The development of reliable, cost-effective, and sensitive detection and monitoring assays is particularly important for the early diagnosis and treatment of cancer. Here, we report an array-based system for cell sensing using a ‘chemical nose/tongue’ approach that exploits subtle changes in the physicochemical nature of different cell surfaces. A family of synthetic and biomolecular functionalized graphene elements was used to develop the sensing array. Their different interactions with dissimilar cell surfaces were transduced to an ultrasensitive electrochemical impedance signal, providing a fingerprint for the classification and identification of different cells. This electrochemical array sensing platform has ultrahigh sensitivity that can detect a single-cell type from one cell. Furthermore, it can discern different cell types at levels as low as 100 cells with high accuracy for (i) different cell types; (ii) cancerous, multidrug-resistant cancerous and metastatic human breast cells; and (iii) artificial circulating tumor cells (CTCs). The graphene-based electrochemical sensing platform presented here can more generally be applied to array sensor fabrication and can provide highly efficient signal transduction pathways to improve the detection response of each recognition element. A graphene-based chemical ‘nose’ can distinguish between healthy cells and different types of cancerous cells. Xiaogang Qu and colleagues from the Changchun Institute of Applied Chemistry in China used seven graphene probes to build a sensor array capable of differentiating cancerous, multidrug-resistant cancerous and metastatic human breast cells from healthy ones. The platform had ultrahigh sensitivity, being able to detect single cells and to discern between different cell types in small samples. The approach works because the surface properties of each type of cell induce different electrochemical responses in the graphene array. Unlike other systems for early cancer detection, this method does not require exact information about types of proteins expressed by these malignant cells, making it broadly applicable for cancer diagnosis in the clinic. An array-based system for cancer cell sensing has been developed by using a ‘chemical nose/tongue’ approach that exploits subtle changes in the physicochemical nature of different cell surfaces. This electrochemical sensing array has ultrahigh sensitivity, which reaches low detection limit (about 1 cell) for the detection of single-cell type and can discern different cell types at level as low as 100 cells with high accuracy, such as (i) different cell types; (ii) cancerous, multidrug-resistant cancerous and metastatic human breast cells; (iii) artificial circulating tumor cells (CTCs).