Development of metal free melamine modified graphene oxide for electrochemical sensing of epinephrine

Metal free material melamine modified graphene oxide (MGO) was prepared by reacting melamine with graphene oxide followed by thermal annealing process. The prepared material was characterized by a range of microscopic and spectroscopic techniques. It was then applied for the detection of epinephrine at a biological pH. An MGO-modified GCE displayed improved electrocatalytic activity by shifting the anodic peak current negatively by 0.1193 V and the cathodic peak current positively by −0.2311 V, compared to those at the GCE. Density Functional Theory (TD-DFT method) was used to predict the electron transfer (ET) sites of MGO. The limit of detection of melamine at the MGO -modified glassy carbon electrode was estimated to be 0.13 µM which indicated the potential application of the electrode to the biosensing of the neurotransmitter epinephrine.