In this study, the authors demonstrate the fabrication, calibration, and testing of a piezoresistive microcantilever-based sensor for biomedical microelectromechanical system (BioMEMS) application. To use any sensor in BioMEMS application requires surface modification to capture the targeted biomolecules. The surface alteration comprises self-assembled monolayer (SAM) formation on gold (Au)/chromium (Cr) thin films. So, the Au/Cr coating is essential for most of the BioMEMS applications. The fabricated sensor uses the piezoresistive technique to capture the targeted biomolecules with the SAM/Au/Cr layer on top of the silicon dioxide layer. The stiffness (k) of the cantilever-based biosensor is a crucial design parameter for the low-pressure range and also influence the sensitivity of the microelectromechanical system-based sensor. Based on the calibration data, the average stiffness of the fabricated microcantilever with and without Au/Cr thin film is 141.39 and 70.53 mN/m, respectively, which is well below the maximum preferred range of stiffness for BioMEMS applications. The fabricated sensor is ultra-sensitive and selective towards Hg2+ ions in the presence of other heavy metal ions (HMIs) and good enough to achieve a lower limit of detection 0.75 ng/ml (3.73 pM/ml).

中文翻译：

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用于 BioMEMS 应用的基于微悬臂梁的压阻传感器的制造、校准和初步测试。

在这项研究中，作者展示了用于生物医学微机电系统 (BioMEMS) 应用的压阻式微悬臂梁传感器的制造、校准和测试。要在 BioMEMS 应用中使用任何传感器，都需要进行表面改性以捕获目标生物分子。表面改变包括在金 (Au)/铬 (Cr) 薄膜上形成自组装单层 (SAM)。因此，Au/Cr 涂层对于大多数 BioMEMS 应用都是必不可少的。制造的传感器使用压阻技术来捕获目标生物分子，其中 SAM/Au/Cr 层位于二氧化硅层的顶部。基于悬臂的生物传感器的刚度 (k) 是低压范围的关键设计参数，也影响基于微机电系统的传感器的灵敏度。根据校准数据，制造的带有和不带有 Au/Cr 薄膜的微悬臂梁的平均刚度分别为 141.39 和 70.53 mN/m，远低于 BioMEMS 应用的最大优选刚度范围。制造的传感器在存在其他重金属离子 (HMI) 的情况下对 Hg2+ 离子具有超灵敏和选择性，并且足以实现 0.75 ng/ml (3.73 pM/ml) 的检测下限。