Electrochemical oxidation of guanosine-5′-triphosphate on a graphene and ionic liquid composite modified carbon molecular wire electrode

A graphene, chitosan and 1-ethyl-3-methylimidazolium tetrafluoroborate composite was prepared and modified on the surface of a carbon molecular wire electrode. The fabricated electrode was characterized by different methods such as scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy . Electrochemical behaviors of guanosine-5′-triphosphate (GTP) were carefully studied on the modified electrode . The electrochemical parameters such as the charge transfer coefficient ( α ) and the electrode reaction standard rate constant ( k s ) were calculated with the results as 0.57 and 1.56   ×   10 −4   s −1 . Under the optimized conditions, the oxidation peak current was proportion to the GTP concentration in the range from 0.007 to 70.0   μmol/L with the detection limit of 0.232   nmol/L (S/N   =   3). Moreover, the proposed method showed good selectivity to the GTP detection without the interference of coexisting substances, and was further applied to the artificial samples determination with satisfactory results.