Cu_(2)O/Cu-垂直石墨烯微电极的制备及尿酸/脑电的检测

Preparation of Cu_2O/Cu-vertical graphene microelectrode and detection of uric acid/electroencephalogram

结合Cu(Ⅱ)离子浸渍吸附方法及直流电弧等离子体喷射化学气相沉积技术制备了一种电化学/电生理双模Cu_(2)O/Cu-垂直石墨烯微电极,并研究了电化学方法检测尿酸以及记录脑电信号的双响应性能。使用扫描电子显微镜、透射电子显微镜、X射线衍射仪表征了形貌、微结构及晶体成分,并测试了电化学及脑电记录能力。结果表明,该微电极直径仅为200μm,大量镶嵌Cu_(2)O/Cu纳米粒子的石墨烯纳米片垂直生长在基片上,排列成了一种三维的多孔结构,使其具有了高的电化学催化活性、短程离子扩散路径、以及长程导电网络。由此,以10μL的饱和NaCl溶液为介质记录脑电信号时,该微电极的皮肤接触电阻低至约7.05 kΩ,生理电采集性能接近涂导电膏的商用湿电极。此外,该微电极还灵敏响应尿酸的氧化电流,检测浓度范围在0.5~500μmol·L^(-1),检测限低至0.024μmol·L^(-1),且具有良好的抗干扰能力及长期稳定性。

A Cu_(2)O/Cu-vertical graphene microelectrode was prepared by combining Cu(Ⅱ) ion impregnation adsorption and direct current(DC) arc plasma jet chemical vapor deposition methods for dual functions including electrochemical detection of uric acid and recording electroencephalogram(EEG) signals.The morphology,microstructure,and crystal composition of the microelectrode were characterized using scanning electron microscopy,transmission electron microscopy,and X-ray diffraction,and the electrochemical and EEG recording capabilities were evaluated.The microelectrode was composed of vertically grown graphene nanosheets embedded with Cu_(2)O/Cu nanoparticles,with a diameter of approximately 200 μm.Because these nanosheets are arranged into a three-dimensional porous structure,the microelectrode has a short ion diffusion path and a long conductive network,which promotes high electrocatalytic activity and electrical performance.The scalp-contact resistance of the microelectrode with physiological saline was as low as 7.05 kΩ.The signal-to-noise ratios of electromyography(EMG),electrooculogram(EOG),and EEG of the microelectrode were close to or exceeded those of a commercial wet electrode coated with conductive gel.In addition,the microelectrode also electrochemically responded to uric acid,with a wide concentration range of 0.5-500 μmol·L^(-1) and a low detection limit of 0.024 μmol·L^(-1),as well as excellent anti-interference and long-term stability.