ZnO多层薄膜声表面波血糖传感器及关键材料研究

Diabetes is one of the three dangerous diseases in the world. Frequent blood sugar testing is necessary for diabetes diagnosis and treatment. However, most of the commercial glucose sensors are of high cost, low sensitivity and vulnerable by interference. Therefore, the development of high-reliability and low-cost glucose sensor has great scientific significance and broad application prospect. Based on the high sensitivity of surface acoustic wave (SAW) device to mass load, this project proposes the use of SAW sensing technology to detect glucose, fabricating a new type of low-cost and high-performance glucose sensor based on ZnO multilayer film SAW device (SAWGB). Three main research contents will be included in this project. Firstly, the growth of ZnO film with high-quality and large piezoelectric coefficient and the control of its preferred orientation.Secondly, the influence of the interlayer on the electromechanical coupling coefficient, insertion loss and operating frequency of ZnO multilayer structure SAW device. Thirdly,the fabrication of ZnO multilayer films SAWGB by coating the sensitive area with pH-sensitive polymer which is bio-functionalized by glucose oxidase immobilization. The effect of preparation and optimization of ZnO piezoelectric material, buffer-layer and sensitive film on the performance of SAWGB will be carefully analyzed, and the impact mechanism of the performance of Love mode ZnO multilayer film SAWGB will be clarified. This work will provide the theoretical basis and experimental guidance for preparing high performance ZnO multilayer films SAWGB.

糖尿病是世界性的三大危险疾病之一，频繁测试血糖是糖尿病诊断和治疗的基础。目前多数血糖传感器成本高、灵敏度低、易受干扰，因而研制高可靠、低成本的血糖传感器具有重大科学意义和广阔应用前景。本项目基于声表面波器件对质量负载高度敏感的特点，提出利用声表面波传感技术来检测血糖，制作新型低成本高性能的ZnO多层薄膜声表面波血糖传感器（SAWGB）。研究适用于Love波SAWGB的高质量、大压电系数的ZnO薄膜生长和择优取向控制，以及中间层选择和厚度设计对ZnO多层薄膜器件机电耦合系数、插入损耗和工作频率的影响机理；在敏感区涂覆pH敏感膜并固定葡萄糖氧化酶构建ZnO多层薄膜SAWGB。深入分析ZnO多层薄膜SAWGB中ZnO压电材料、中间层材料和敏感膜材料制备和优化对SAWGB性能的影响规律，阐明影响Love波ZnO薄膜SAWGB性能的机制，为制备高性能ZnO多层薄膜SAWGB提供理论依据和实验指导。

糖尿病是世界性的三大危险疾病之一，频繁测试血糖是糖尿病诊断和治疗的基础。目前多数血糖传感器成本高、灵敏度低、易受干扰，因而研制高可靠、低成本的血糖传感器具有重大科学意义和广阔应用前景。本项目构建了新型低成本高性能的ZnO多层薄膜声表面波血糖传感器（SAWGB），研究了适用于Love波SAWGB的高质量、大压电系数的ZnO薄膜生长和择优取向控制，包括溅射气压，氧气和氩气的分压等的影响；研究了中间层（SiO2/AlN）对ZnO多层薄膜器件机电耦合系数、插入损耗和工作频率的影响；研究了在敏感区固定pH敏感膜和葡萄糖氧化酶的方法，构建了ZnO多层薄膜SAWGB。研究发现Zn0.92Mn0.08O薄膜的压电系数高达80pC/N以上，优化的ZnO/SiO2/Si三层结构声速可达3500m/s以上，机电耦合系数达到2.7%以上，SiO2中间层不仅能够提高三层结构的声速，还能改善三层结构的温度稳定性，得到温度系数接近于0的三层结构，并且有效激发出Love波；构建的ZnO/SiO2/Si三层结构SAWGB的检测下限达到6.29×10-4 mM，灵敏度达到1.589MHz/mM，实现血糖含量从监测下限到20mM的检测范围。通过AlN中间层来诱导ZnO薄膜的择优取向，发现在具有(110)择优取向的AlN薄膜上容易生长出(110)择优取向的ZnO薄膜。研究了ZnO和AlN薄膜不同的厚度制作的声表面波器件的机电耦合系数和声速，ZnO/AlN/Si多层薄膜结构的声速最高达5160m/s，机电耦合系数最大达5.3%，插入损耗最小-16dB， AlN中间层不仅能够提高三层结构的声速，还能改善三层结构的温度稳定性。在高声速，大机电耦合系数和低插入损耗的ZnO/AlN/Si多层薄膜结构声表面波谐振器的敏感区涂覆pH敏感膜并固定葡萄糖氧化酶构建ZnO/AlN/Si多层薄膜SAWGB，研究发现ZnO/AlN/Si多层薄膜SAWGB的敏感度达到1.819 MHz/mM,检测极限达到~1.65×10-5 mM，SAWGB表现出具有良好的线性特性。对比SiO2和AlN中间层，AlN中间层能够获得更好的性能，但是其制备难度比较大。中间层的结构特性和厚度对Love波ZnO薄膜SAWGB性能影响较大。本项目开展的ZnO多层薄膜结构SAWGB有望为糖尿病人的血糖测试提供一种高性能、价格低廉的新型血糖传感器。