A generic electrochemical method of "bioreceptor" antibody attachment to phenyl amine functionalised graphitic surfaces is demonstrated. Micro-channels of chemically modified multi-layer epitaxial graphene (MLEG) have been used to provide a repeatable and reliable response to nano molar (nM) concentrations of the cancer risk (oxidative stress) biomarker 8hydroxydeoxyguanosine (8-OHdG). X-ray photoelectron spectroscopy, Raman spectroscopy are used to characterize the functionalised MLEG.

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... fluorescence microscopy using fluorescent-labelled antibodies indicates that the anti-8-OHdG antibody selectively binds to the phenyl amine-functionalised MLEG's channel. Current-voltage measurements on functionalised channels showed repeatable current responses from antibody-biomarker binding events. This technique is scalable, reliable, and capable of providing a rapid, quantitative, label-free assessment of biomarkers at nano-Molar (less than 20 nM) concentrations in analyte solutions. The sensitivity of the sensor device was investigated using varying concentrations of 8-OHdG, with changes in the sensor's channel resistance observed upon exposure to 8-OHdG. Detection of 8-OHdG concentrations as low as 0.1ng/ml 1 Corresponding authors.