基于氮化钛–石墨烯的传感器对多巴胺和尿酸的电化学检测

Electrochemical detection of dopamine and uric acid using a titanium nitride-graphene composite sensor

采用水热法和还原氮化法合成了菊花状形貌的氮化钛(TiN)纳米材料,并将其与还原氧化石墨烯(rGO)水热复合制备了氮化钛–还原氧化石墨烯(TiN-rGO)复合材料.利用扫描电镜、X射线衍射、X射线光电子能谱等测试方法对材料的形貌和物相进行了表征和分析.结果表明,TiN-rGO复合材料很好地保持了TiN菊花状的三维结构和rGO透明褶皱的形貌,且层状的rGO均匀地包覆在了菊花状的TiN的周围.用TiN-rGO复合材料修饰玻碳电极(GCE)制得了TiN-rGO/GCE电化学传感器,用于测定人体中的生物小分子DA和UA.由于复合材料中TiN和rGO的协同效应,构建的电化学传感器表现出了优秀的电化学性能.检测结果表明:TiN-rGO/GCE传感器对DA和UA的检测限分别为0.11和0.12μmol·L^-1,线性范围分别为0.5~210μmol·L^-1和5~350μmol·L^-1,且具有良好的抗干扰性、重现性和稳定性,且成功应用于人体内真实样品的DA和UA检测.

Dopamine(DA)and uric acid(UA)are small biological molecules involved in many important processes in the human body.Their concentrations are closely related to human health.Abnormal concentrations of these molecules lead to various diseases,such as Parkinson's and gout,so monitoring of DA and UA in blood and urine,respectively,is very meaningful in clinical analysis.Electrochemical sensor detection is a widely-used method in the field of biological analysis owing to its advantages of simple operation,high sensitivity,low cost,environmental friendliness,etc.In this paper,titanium nitride(TiN)nanomaterial with chrysanthemum morphology was synthesized by hydrothermal and reduction nitridation methods toward preparation of an effective electrochemical sensor for human testing.It was further combined with reduced graphene oxide(rGO)through the hydrothermal method to form a titanium nitride-reduced graphene oxide(TiN-rGO)composite material.The phase and morphology of the material were characterized and analyzed by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and other test methods.The results show that the TiN-rGO composite material maintaines the three-dimensional chrysanthemum-like morphology of TiN,and the transparent and wrinkled morphology of rGO.The chrysanthemum-like TiN is uniformly coated with the layered rGO.The TiNrGO/GCE electrochemical sensor was then prepared by modifying the glassy carbon electrode(GCE)with TiN-rGO composite material for the determination DA and UA levels in the human body.Due to the synergistic effect of TiN and rGO in the composite,the constructed electrochemical sensor exhibits excellent electrochemical performance.The detection results show that the detection limits of DA and UA for the TiN-rGO/GCE electrochemical sensor are 0.11 and 0.12μmol·L^-1,respectively,and the linear ranges are 0.5‒210μmol·L^-1 and 5‒350μmol·L^-1,respectively.TiN-rGO/GCE electrochemical sensor also has good anti-interference,reproducibility and stability,and has been successfully applied in the detection of DA and UA in real human samples.