聚咪唑/氮化碳新型纳米复合材料修饰电极对尿酸、黄嘌呤和次黄嘌呤的同时检测

以三聚氰胺为原料, 采用热聚合法合成了类石墨烯状二维片状氮化碳(g-C₃N₄)纳米材料; 通过电沉积和高电位氧化的方法制得氧化聚咪唑(PImox)/g-C₃N₄修饰电极(PImox/g-C₃N₄/GCE). 采用扫描电子显微镜(SEM)和X射线粉末衍射仪(XRD)对g-C₃N₄纳米材料进行了表征; 通过循环伏安法(CV)和差分脉冲伏安法(DPV)考察了尿酸(UA)、 黄嘌呤(XA)和次黄嘌呤(HX)在该电极上的电化学行为. 结果表明, UA, XA和HX的检测线性范围分别为2.0~216.0, 5.0~542.0和5.0~778.0 μmol/L; 检出限分别为0.17, 0.30和0.30 μmol/L. 将该修饰电极用于实际样品(血清和尿液)中UA, XA和HX的同时测定, 加标回收率为98.4%~105.2%.

Simultaneous Determination of Uric Acid,Xanthine and Hypoxanthine Based on Polyimidazole/Carbon Nitride Novel Nanocomposite†

Two dimensional(2D) sheet-like structure of carbon nitride(g-C₃N₄) nanosheets containing winkles were synthesized, which were analogous to the crumpled graphene. At the same time, overoxidized polyimidazole(PImox)/g-C₃N₄ modified electrode(PImox/g-C₃N₄/GCE) was prepared by electrodeposition and oxidation at higher potentials. The composite materials were characterized by scanning electronmicroscopy(SEM) and X-ray diffractometry(XRD). The electrochemical behaviors of uric acid(UA), xanthine(XA) and hypoxanthine(HX) at the PImox/g-C₃N₄/GCE were investigated using cyclic voltammetry(CV) and differential pulse voltammetry(DPV). The calibration curves for UA, XA and HX were obtained over the ranges of 2.0—216.0, 5.0—542.0 and 5.0—778.0 μmol/L with the detection limits of 0.17, 0.30 and 0.30 μmol/L, respectively. PImox/g-C3N4/GCE has lower detection limits and wider linear range for simultaneous detection of UA, XA and HX. In addition, the modified electrode was applied to detect UA, XA and HX in real samples using standard addition method with satisfactory results. The recovery rates of the samples ranged between 98.4% and 105.2%.