Graphene Functionalized Graphite Electrode with Diphenylacetylene for Sensitive Electrochemical Determination of Adenosine-5′-triphosphate

In this paper a molecular wire modified carbon paste electrode (MW-CPE) was firstly prepared by mixing graphite powder with diphenylacetylene (DPA). Then a graphene (GR) and chitosan (CTS) composite film was further modified on the surface of MW-CPE to receive the graphene functionalized electrode (CTS-GR/MW-CPE), which was used for the sensitive electrochemical detection of adenosine-5′-triphosphate (ATP). The CTS-GR/MW-CPE exhibited excellent electrochemical performance and the electrochemical behavior of ATP on the CTS-GR/MW-CPE was carefully studied by cyclic voltammetry with an irreversible oxidation peak appearing at 1.369 V (vs. SCE). The electrochemical parameters such as charge transfer coefficient ( α ) and electrode reaction standard rate constant ( k s ) were calculated with the results of 0.53 and 5.28×10 −6 s −1 , respectively. By using differential pulse voltammetry (DPV) as detection technique, the oxidation peak current showed good linear relationship with ATP concentration in the range from 1.0 nM to 700.0 µM with a detection limit of 0.342 nM (3 σ ). The common coexisting substances, such as uric acid, ascorbic acid and guanosine-5′-triphosphate (GTP), showed no interferences and the modified electrode was successfully applied to injection sample detection.