Preparation Of Cu/CuO-Vertical Graphene Microelectrode For The Simultaneous Determination Of Epinephrine And 2-Aminoadenosine

It is of great significance to investigate the metabolism of physiological active substances and the change of drug content for human health examination and medical research,and electrochemical method is suitable for in situ and rapid detection of analytical means.Epinephrine(Ep)is a neurotransmitter commonly found in the human body,while 2-adenosine amino(AAD)is an anti-cancer drug intermediate that affects the nervous system.In this paper,a novel electrochemical sensor based on Cu/CuO-vertical graphene(VG)microelectrode is prepared for the simultaneous detection of Ep and AAD.Firstly,various flexible Cu/CuO-VG microelectrodes with diameters of about200 μm were prepared in one step by electronic assisted hot wire chemical vapor deposition.These microelectrodes consist of graphene nanosheets embedded with a large number of Cu/CuO nanoparticles and grown vertically on Ta microfilaments to form sensing components.The optimized Cu/CuO-VG microelectrode has high sensitivity for the single,selective and simultaneous detection of Ep and AAD due to the synergistic effect of the electrocatalytic activity of Cu/CuO nanoparticles and a large number of graphene nanosheets,volume adsorption of ions by VG films and long-range electron transport networks.Secondly,the optimized Cu/CuO-VG microelectrode can quantitatively detect Ep and AAD in p H 5.0～9.0.The detection limits(S/N = 3)of Ep and AAD were0.13～0.18 μM and 0.13～0.19 μM respectively.The sensor electrode has high selectivity,repeatability and long-term stability for Ep and AAD detection.In addition,the quantitative detection of Ep and AAD in human serum and urine was carried out using flexible Cu/CuO-VG microelectrodes.The recoveries reached92.92～106.56% and 90.64～106.87%,respectively,which confirmed the reliability of the real sample detection.