为满足大规模胃癌早期筛查对胃蛋白酶原I(PGI)检测高灵敏度、高效率、操作简单、样品量少的需求, 本文构建了一种PGI抗体功能化薄膜型Lamb波生物传感器。对传感器检测腔薄膜进行PGI抗体自组装修饰, 传感器检测腔表面修饰的PGI抗体将样品中PGI抗原特异性的捕获并固定在检测腔薄膜表面, Lamb波传感器薄膜表面质量增加导致其A0模式中心频率发生移动, 且频率移动量与检测腔表面吸附物质质量增加量正相关, 实现对样本中PGI抗原浓度的检测。实验结果表明: PGI抗体功能化薄膜Lamb波生物传感器对PGI抗原实测灵敏度约为102.114 Hz/ng/mL, 理论最低检测限(LOD)为0.176 ng/mL, 单个样本检测时间为40 min, 与现有基于光学检测法PGI检测技术相比, 具有检测系统简单、操作简单、不需要专业人员操作等显著优势, 且比多数光学检测法LOD更低, 比电化学法PGI检测技术LOD低两个数量级。结果表明, 本文提出的PGI抗体免疫功能化薄膜型Lamb波生物传感器对PGI检测且具有检测下限低、灵敏度高、检测效率高、操作简单、无需样品预处理等特点, 满足大规模早期胃癌筛查的基本需求。

To achieve the requirements of high sensitivity, high efficiency, simple operation, and low sample size for the detection of pepsinogen I (PGI) in large-scale early screening of gastric cancer, a thin-film Lamb wave device with PGI antibody functionality was constructed in this study. The thin film in the device detection cavity was modified with self-assembly of the PGI antibody, which specifically captured and immobilized the PGI antigen in the samples on the surface of the thin film. The resultant increase of mass on the surface led to change of the A0 mode center frequency, and the variation was positively correlated with the increment of mass absorbed on the chamber surface. Thus, the PGI antigen concentration in the samples was detected. The results showed that, when measuring the level of the PGI antigen, the thin-film resonance Lamb wave biosensor with PGI antibody functionality had a sensitivity of about 102.114 Hz/lg (ng/mL), theoretical limit of detection (LOD) of 0.176 ng/mL, and detection time for one sample of 40 min. Compared with the existing PGI detection technology based on optical detection, the Lamb wave sensor has the advantages of being a simple detection system with simple operation and no need for professional operators, and lower LOD than most optical detection methods, two orders lower than that of the electrochemical method of PGI detection. In conclusion, the thin-film resonance Lamb wave biosensor with PGI antibody functionality proposed in this paper has the advantages of low LOD, high sensitivity, high detection efficiency, and simple operation, which can satisfy the basic requirements of large-scale early gastric cancer screening.