Dynamic tracking of pathogenic receptor expression of live cells using pyrenyl glycoanthraquinone-decorated graphene electrodes† †Electronic supplementary information (ESI) available: Experimental section, additional figures and original spectra copy of new compounds. See DOI: 10.1039/c4sc03614j Click here for additional data file.

Expression of specific transmembrane receptors by cells frequently represents an important signature of diseases, but this dynamic event can hardly be monitored directly with live cells due to the limitation of current biochemical techniques. Here we develop a pyrenyl glycoanthraquinone construct that can be firmly immobilized on a graphene-spotted screen printed electrode via strong p-interactions. The inherent current signal produced by the surface-confined glycoquinone can be used to detect selective sugar–protein recognitions with simple electrochemical techniques and portable facilities. Importantly, we demonstrate that the level of pathogenic receptors expressed by different types of live cells can be tracked with the electrode system in a label-free manner, providing a useful tool for the on-demand disease diagnosis as well as basic biochemical studies.