Design and Fabrication of a Novel Biomass Sensor

目前，人们对新型生物传感器有着极大的兴趣和需求，以在越来越低的浓度下检测越来越多的不同分析物。本文首次提出了一种能够测量飞秒量级质量的新型超灵敏MEMS质量传感器。该传感器由一组悬臂梁围绕的旋转盘组成，悬臂梁通过固定的悬臂电极被静电激励。将对申报器械进行甲胎蛋白（AFP）检测试验，AFP是肝癌的生物标志物。肝癌是少数几种细胞毒性化疗效果甚微的肿瘤之一，这证明早期诊断可以提高生存率。将测定该生物传感器的灵敏度、选择性和检测限。我们打算揭示潜在的非线性动力学和减少在该领域的知识gap.建议的MEMS传感器/开关利用面内旋转运动，以克服传统的悬臂梁MEMS传感器的out-ofplane运动的复杂性，并相应地导致与石英晶体微天平技术相比，提高了灵敏度。此外，考虑到生物质与谐振器质量的比率，生物质对悬臂梁的位置依赖性变得更加明显。由于所提出的模型的独特架构，传感器的输出将独立于生物标志物的位置和受体的沉积，并且生物标志物将不会改变传感器的刚度。因此，所提出的生物质传感器提供了超过可用的基于生物质的生物质传感器的灵敏度，而不需要按比例缩小到纳米范围，这显著地需要更高的制造成本并增加复杂性。这使得能够实时和超高灵敏度地快速检测各种生物量（例如与不同疾病相关的生物标志物）。

Currently, there is immense interest and demand for novel biosensors to detect a growing number of diverse analytes at increasingly low concentrations. Here for the first time, a novel ultra-sensitive MEMS mass sensor is proposed capable of measuring masses in the order of femtogram. The sensor consists of a rotational disk surrounded by a group of moving cantilever beams which are electrostatically excited through the fixed cantilever electrodes. The proposed device will be tested for the detection of alphafetoprotein (AFP), which is a biomarker for liver cancer. The liver cancer is one of the few tumors for which cytotoxic chemotherapy has little effect and this justifies the early-stage diagnosis of it for more survival. The sensitivity, selectivity and detection limit of the biosensor will be determined. We intend to uncover the underlying nonlinear dynamics and reduce the knowledge gap in the field.The proposed MEMS sensor/switch takes advantage of the in-plane rotational motion to overcome the complications of the out-ofplane motion of traditional cantilever MEMS sensors and accordingly results in enhanced sensitivity in comparison with Quartz Crystal Microbalance technology. Furthermore, considering the ratio of the biomass to the resonator mass the position dependency of the biomass on the cantilever beam becomes more pronounced. Due to the unique architecture of the proposed model, the output of the sensor will be independent of the position of the biomarker and the deposition of the receptor, and the biomarker will not change the stiffness of the sensor. Therefore, the proposed biomass sensor offers a sensitivity beyond the available cantilever-based biomass sensors without the need to scale down to nano regime, which significantly demands higher fabrication costs and increases complexities. This enables the rapid detection of a wide range of biomasses (such as biomarkers associated with different diseases) in real-time and at ultra-high sensitivity.