Photonic Crystal System for Single Bioparticle Detection

开发快速、灵敏和易于使用的生物传感器来检测各种病原体仍然是国家的重要任务。检测病毒的传统诊断方法很复杂，需要训练有素的技术人员操作。这种复杂性和成本显然是不可取的，因为它大大延长了在临床环境中进行诊断所需的时间，并严重限制了在设备齐全的实验室和训练有素的人员可用的地方部署传感器和诊断。光学无标签生物传感器平台的开发有望简化系统的复杂性，同时表现出理想的性能，是一个高度优先考虑的问题。提出了一种基于二维光子晶体微腔的单生物粒子检测平台，该微腔采用微电子工艺在绝缘体硅衬底上制备。在这些装置中捕获生物颗粒局部增加折射率，这可以通过光传播波长的移动来检测。光子晶体微腔将被设计、制造、测试和优化，以获得最大的光透射率，以及对感兴趣目标的灵敏度和选择性。它们将与微流体集成，包括一种由硅制成的新型超薄膜过滤器，用于预先浓缩目标。将探索表面增强拉曼散射（SERS）和二维PhC微腔的结合，以使识别明确并消除假阳性响应。拟议的工作回应了对新型病毒性病原体（包括严重急性呼吸系统综合症或SARS和H5N1“禽流感”）迅速增加的日益严重的关切，以及对可能使用天花等病毒性病原体作为生物战剂的持续关切，为此，全球研究界将开发能够检测单个病毒颗粒的无标签生物传感器作为主要目标。拟议的研究不仅将为危险病毒的检测提供策略，还将为广泛的生物靶点提供策略。

CBET-0730469 Fauchet The development of rapid, sensitive and easy-to-use biosensors for the detection of a wide range of pathogens continues to be of national importance. Traditional diagnostic methods for the detection of viruses are complex and require operation by a highly trained technician. This level of complexity and cost is obviously undesirable, as it significantly lengthens the time necessary to make a diagnosis in a clinical setting, and severely limits the deployment of sensors and diagnostics to locations where both fully equipped laboratories and trained personnel are available. The development of optical label-free biosensor platforms, which promise to simplify the system complexity while exhibiting desirable performance, is a high priority. Intellectual Merit A novel platform for single bioparticle detection is proposed, which is based on two-dimensional photonic crystal microcavities fabricated on silicon-on-insulator substrates using microelectronic fabrication steps. Capture of bioparticles in these devices locally increases the refractive index, which can be detected as a shift of the wavelength of light propagation. The photonic crystal microcavities will be designed, fabricated, tested, and optimized for maximum light transmission, and for sensitivity and selectivity to the targets of interest. They will be integrated with microfluidics including a novel ultrathin membrane filter made of silicon that will be used to pre-concentrate the targets. The combination of surface-enhanced Raman scattering (SERS) and 2-D PhC microcavities will be explored to make identification unambiguous and eliminate false positive responses. Broader Impact The proposed work responds to mounting concern over the rapid rise of new viral pathogens (including Severe Acute Respiratory Syndrome, or SARS, and the H5N1 "bird flu"), as well as continuing concern over the possible use of viral pathogens such as smallpox as biowarfare agents, in response to which the global research community has targeted the development of label-free biosensors capable of detecting single virus particles as a major goal. The proposed research will provide strategies for the detection of not only dangerous viruses but also a wide range of biological targets.