由于当代人的饮食结构变化，高尿酸血症及其继发的多种严重病症正在加剧危害中国人的身体健康。传统医疗检测和实验室分析方法因其昂贵、操作复杂且庞大的设备体积，已不能满足人们对快速、准确且微创的血液尿酸检测需求。因此，简单有效的全血尿酸浓度传感器有着很高的研究价值和应用前景。本研究从电极改性方法、尿酸电化学传感器选择性以及全血检测三方面出发，设计制作了特殊褶皱形貌电化学金电极，理论探索和实验测试了干扰物选择性与器件表面形貌之间的关系，对溶液样品实现了尿酸的高线性度的检测，最终将其应用于血液样本，实现了全血尿酸电化学检测。从电极改性角度出发，提出了基于热收缩膜的电极物理重构方法，利用该方法制作的金电极表面的特殊褶皱形貌提供了更大的反应面积以及优良的电化学反应场所，有更好的尿酸电化学催化性能；该电极对于尿酸的电化学检测灵敏度提升显著，响应电势负偏95 mV，峰值响应增强2.3倍，实现了大范围尿酸浓度线性检测，并具有良好的重复性和长期稳定性。从尿酸检测的选择性出发，分析了热收缩膜改性金电极对于尿酸电化学反应增强的微观机制，以及对葡萄糖、维生素C选择性的提升机制；系统地对比了商用金电极、玻碳电极以及热收缩前后的金电极的尿酸电化学响应，验证了热收缩导致的物理改性对尿酸电化学反应增强作用；通过干扰物共存电化学实验，验证了热收缩膜改性金电极器件检测尿酸的选择性提升效果。最终，将热收缩改性金电极应用于全血样本的尿酸浓度直接检测，设计了平面三电极器件，利用镂空模板成型工艺实现了器件的制作；对血液样品中尿酸浓度测试结果表明，响应信号与尿酸浓度有很好的线性关系，线性范围100~500 μM，检测下限63 μM。与此同时，表面光滑的金电极在同样的电化学环境中，由于血液中的血细胞对反应物质的迁移阻挡作用，并未观察到尿酸的电化学信号。关键词：尿酸电化学传感器；热收缩膜；电极形貌；选择性提升；全血检测
Due to modern dietary changes, Hyperuricemia and its harmful secondary diseases have become increasingly prevalent among the Chinese. Traditional medical methods and laboratory analysis are expensive and complicated to operate, with bulky instrumentations, which are far beyond the needs of accurate minimally invasive test in real time. Therefore, a simple and effective uric acid sensor towards real blood test has high research value and wide application prospect. This thesis states the research status of the uric acid sensor for real blood test, aims at the electrode modification methods, selectivity problems of non-enzymatic electrochemical uric acid sensor and tests on real blood sample. A gold electrode with unique wrinkled surface structure is designed and accomplished with shrink polymer and simple electrode fabrication way. Linear response towards aqueous uric acid is revealed experimentally, possible principles linking the electrode surface morphology and the selectivity are proposed and discussed. The whole blood sensor towards uric acid is also realized, employing this technique.Physical remodeling method based on gold films on shrink polymer is proposed, aiming in electrode modification. Outstanding electrochemical properties of the remodeled electrode are employed: the unique wrinkled structure of the electrode surface gives a rise in reaction area, shows better catalytic ability towards uric acid oxidation with better reaction region on it. The electrochemical properties improve a lot, with the evidence that the 95 mV negatively shifting peak potential and 2.3 times response enhancement. Response towards uric acid is realized, with large linear range, good repeatability and long-term stability.Mechanisms of the reaction enhancement and selectivity improvement due to the wrinkled gold are proposed and discussed, aiming in selectivity solution of non-enzymatic uric acid electrochemical sensors. Systematic comparison of the electrochemical responses of uric acid/glucose/ascorbic acid/dopamine on different types of electrode is carried out, shows the necessity of the physical electrode remodeling on shrink polymer. Selectivity improvement data is presented along with the coexisting experiments. Mechanisms underneath are also discussed.Real blood test towards uric acid is verified on this shrink sensor, shows the significance of the wrinkled electrode structure. A planar three electrode sensor is designed and fabricated, with a simple electrode fabrication way using shadow masks. A signal enhancement is observed, and good linear response towards uric acid is also achieved. The linear range is 63~500 μM, with detection limit of 63 μM. The smooth gold electrode counterpart without shrinking procedure shows no observable reaction peak, due to the diffusion barrier effect of the hemocyte.Keywords: non-enzymatic uric acid electrochemical sensor; heat-shrinkable polymer; electrode morphology; selectivity improvement; real blood test
