SGER: Integrated InP Microcantilever Biosensors Using Chitosan Interface Layer

本研究的目的是为研究壳聚糖生物高分子材料在InP光学MEMS/NEMS检测平台上的选择性沉积和光力学表征奠定基础。本次SGER项目将开展以下三项工作：(a)壳聚糖电沉积条件将采用组合方法进行表征，以获得最佳的InP微结构膜的形貌和厚度；(b)基于最佳壳聚糖电沉积结果修改InP光学MEMS/NEMS平台的设计，以最大化位移灵敏度；(c)利用InP光学MEMS/NEMS器件首次演示了探针DNA分子共轭到壳聚糖膜上的DNA杂交检测。我们提出的设计的主要优点是它可以实现单芯片便携式生物危害检测。微悬臂传感器已被证明是不需要标记样品的强大分析工具。片上光学检测将提供适合便携式设备的小型化但高灵敏度的读出方案。此外，使用壳聚糖作为生物界面会增加悬臂梁的目标生物分子密度，从而产生较大的共振频移。该检测系统兼容批量微细加工。可以在同一芯片上并行制造大量传感器，以非常低的成本和高通量筛选不同的分析物。由此产生的设备将是小的，便宜的，并且将需要最少的样品制备和不需要外部读出设备。这项技术将导致开发微悬臂传感器，在偏远地区筛查疾病和生物危害剂，而不需要高素质的实验室技术人员或设备。该项目在马里兰大学（UMD）也将具有相当大的教育价值。这项工作将主要招收美国本科生和研究生。这项研究的概念将被转移到两个研究生水平的基于项目的MEMS课程，ENEE 605和ENEE 719F，在马里兰大学电气和计算机工程系（ECE）。这项研究的结果也将用于K-12的外展活动，包括春季学期的马里兰日。1

The objective of this (SGER) is to develop the foundation for investigating the selective deposition and opto-mechanical characterization of chitosan biopolymer material on the InP optical MEMS/NEMS detection platform. . The following three tasks will be conducted for this SGER program: (a) Chitosan electrodeposition conditions will be characterized using a combinatorial approach to achieve optimal morphology and thickness of the film on the InP microstructures, (b) Design of the InP Optical MEMS/NEMS platform will be modified based on the optimum chitosan electrodeposition results to maximize displacement sensitivity, (c) DNA hybridization detection with probe DNA molecules conjugated to the chitosan film will be demonstrated for the first time using InP optical MEMS/NEMS devices. Intellectual Merit The major advantage of our proposed design is that it will enable single-chip portable detection of biohazards. Microcantilever sensors have been shown as powerful analytical tools that do not require labeling of the sample. The on-chip optical detection will provide a miniaturized yet highly sensitive readout scheme appropriate for portable devices. In addition, the use of chitosan as a biointerface will increase the target biomolecule density of the cantilever, resulting in large resonant frequency shifts. The detection system proposed is compatible with batch microfabrication. Large numbers of sensors can be fabricated in parallel on the same chip to screen for different analytes with very low cost and high throughput. Broader Impact The resulting devices will be small, inexpensive, and will require minimal sample preparation and no external readout equipment. This technology will result in developing microcantilever sensors to screen for diseases and biohazard agents at remote locations without the need for highly qualified laboratory technicians or equipment. This project will also have considerable educational value at the University of Maryland (UMD). Primarily U.S. undergraduate and graduate students will be recruited for this work. The concepts of this research will be transferred to the two graduate-level project-based MEMS courses, ENEE 605 and ENEE 719F, in the Electrical and Computer Engineering Department (ECE) at UMD. The outcome of this research will also be used for K-12 outreach activities including Maryland Day in spring semesters. 1