面向糖尿病酮症酸中毒诊断的CeO2基混成电位型丙酮气体传感器的研究

By detecting the concentration of the acetone with the portable detector, the ketoacidosis could be non-invasively diagnosed and real-time monitored for people with diabetes, which is of great significance for clinical medicine and home caring. There is no doubt that developing the acetone sensor with high sensitivity, great selectivity and excellent moisture resistance is the key and the basis to develop the low-cost and smart acetone detector. On a basis of the mixed-potential mechanism, the project is focused on the fabrication of solid-state acetone sensor using metal oxide as electrode and CeO2 as electrolyte. Specifically, by optimizing parameters of doping and sintering, the conductivity, density, mechanical strength and the thick-film quality could be improved, which could provide excellent electrolyte for the sensor; By optimizing the composition of the metal oxide of the electrode material, fabricating the porous electrode, and constructing porous nanoscale three-phase with high performance (the two-level enhancement tactic), the sensitivity and the selectivity are improved significantly, with the lower limit for detection falling to 100ppb; By constructing planar array with gas sensor and humidity sensor, and by compensating the humidity for the acetone sensor with the grapheme /oxide humidity sensing element, the moisture resistance of the sensor is enhanced significantly. Taking advantage of the innovative research in a systematic way, the mixed-potential acetone sensor could meet the requirements of the diagnosing of the ketoacidosis, and at the same time, more breakthrough of the sensing mechanism is also expected.

通过便携式检测仪测量呼气中的丙酮浓度，可以对糖尿病患者的酮症酸中毒病况进行无创伤诊断和实时监控，在临床医学和在宅监护上具有重要意义。研制高灵敏、高选择和高抗湿的丙酮传感器是开发低成本和小型化丙酮检测仪的基础和关键。本项目基于混成电位感知机理，利用CeO2固体电解质和金属氧化物电极构建全固态丙酮传感器。通过掺杂和烧结技术的优化来提高CeO2固体电解质的电导率、密度、机械强度和厚膜质量，为构建丙酮传感器奠定材料基础；通过氧化物敏感电极材料的组成优化和多孔化设计以及高性能多孔纳米三相反应界面的构筑（两级增感策略），提高传感器的灵敏度和选择性，使检测下限达到100ppb；设计气体传感器和湿度传感器的平面阵列结构，利用石墨烯/氧化物湿敏元件对丙酮传感器进行高精度湿度补偿，以提高抗湿性。通过系统的创新性研究，使混成电位型丙酮传感器满足酮症酸中毒诊断要求，同时希望在新型感知机制探索方面取得新突破。

本项目通过开发新型固体电解质材料、制备具有高电化学催化活性的敏感电极材料、构筑纳米多孔三相反应界面、构建糖尿病酮症酸中毒检测用检测仪等系统工作，研制出满足糖尿病酮症酸中毒预诊断性能指标要求的丙酮传感器和检测仪。在项目运行的4年里，项目组在国际上率先开展氧化铈（CeO2）固体电解质基混成电位型传感器的研究，共开发了BiFeO3、SrMnO3、La0.8Sr0.2CoO3、Bi0.5La0.5FeO3、Sr2FeMoO6五种用于构建CeO2基混成电位型传感器的敏感电极材料，其中，以Sr2FeMoO6为敏感电极材料的传感器对5-500ppm丙酮的灵敏度达到了100mV/decade，检测下限可以达到0.5ppm，对100ppm的响应时间只有13s。在前期工作的基础上，继续开展稳定氧化锆（YSZ）固体电解质基混成电位型丙酮传感器的研究，开发了Sm1.4Sr0.6NiO4、Co0.5Zn0.5Fe2O4、CdMoO4、Zn3V2O8、NiNb2O6和CdNb2O6六种高性能的敏感电极材料用于构建YSZ基混成电位型丙酮传感器，其中，以CdMoO4为敏感电极材料的传感器对5-500ppm丙酮灵敏度都达到了84mV/decade，其检测下限达到0.5ppm，对300ppm丙酮响应时间只有14s。以Co0.5Zn0.5Fe2O4为敏感电极的传感器的检测下限可达到0.3ppm，完全满足糖尿病酮症酸预诊断对传感器检测下限的要求。开发的混成电位型传感器对不同血酮含量病人呼气的响应值与糖尿病人的血酮浓度对数成很好线性关系，这说明利用我们的传感器能准确地判断糖尿病人的病情。开发的10余种混成电位型丙酮传感器主要参数都达到了申请书中的指标。通过本项目的实施，开发的传感器可以实现对糖尿病患者的酮症酸中毒病况进行无创伤诊断和实时监控，研究工作在临床医学和在宅监护上具有重要意义。在项目完成的过程中，项目组已在Sensors and Actuators B、ACS Appl. Mater. Interfaces等权威刊物上发表SCI论文41篇，其中，第一标注15篇；申请国家发明专利19项，其中授权8项。已经培养教授2名，副教授2名，高级工程师1名，培养研究生11名(其中3名博士生、8名硕士生)。项目组成员在全国气湿敏会议上做邀请报告1次，国际学术会议作分会场报告5次。