SENSORS: Arrayed Optical Detection of Nanoscale Biomass

AbstractIntellectual MeritThis传感器提案的重点是检测少量材料的能力，包括致病细菌和细胞反应中不可或缺的生物分子。提出了新的方法来转导质量变化的问题和片上复用和解复用的问题。这些想法是基于先进的MEMS和集成光学器件开发的概念。 目前大多数检测技术要么体积庞大、昂贵，要么速度缓慢。我们提出了一种新的设备/仪器，用于超灵敏检测分子量的材料，在病原体和生化检测，医学，药物发现和纳米技术的应用。 所提出的技术允许通过光纤连接结构检测内在网络结构中的不同目标的阵列。该技术通过使用一次性无源芯片，以低成本实现高吞吐量。该器件由绝缘体上硅基芯片组成，该芯片将超灵敏纳米机械杠杆与新型硅基无源集成光学器件相结合。无源光学环形谐振器用于光信号的片上波长复用和解复用。 环形谐振器充当不同波长的滤波器，这些波长被引导到不同的悬臂梁传感器。悬臂梁波导用于运动检测。MHz范围内的机械振动通过生物敏化悬臂梁换能器阵列的一个元件编码在光信号上。单个波长与不同悬臂梁传感器的机械振动的一对一关联允许人们寻址每个感测部位。换能策略的这种创新允许使用不需要外部调谐或闭环控制的环形谐振器。此外，该策略需要用于光载波信号的廉价宽带源。在每个环形谐振器/悬臂对处感测到的振动频率的偏移可以在外部设备上并行检测。生物传感器的工作原理是基于病原体对硅纳米结构的高灵敏度、免疫特异性附着。除了检测其存在外，还测量病原体的质量。我们的初步研究结果表明，电子天平能够检测到的质量在阿图克皮克范围内。质量的附加信息允许筛选假阳性，大大提高了方法的效率。IC兼容制造技术允许一次性芯片的成本真正最小化。从这种方法中出现的是各种病原体的干质量的高分辨率测量的可能性，从大型单细胞生物体到病毒和大型大分子。这种新颖的硅基纳米光子运动检测方案允许阵列的这种设备，以形成一个完整的硅平台，降低成本，提高灵敏度和巨大的系统级集成革命性的功能，成本和portable.Broader ImpactsThis研究将使大规模的廉价紧凑的测试，今天只做了几个专门的实验室。这将有助于预防和诊断当今的疾病和生物危险材料。人们可以想象，例如，在战场上，士兵将传感器放在口袋里，检测到生物战中使用的非常微量的危险化学品，或者在医生的办公室或家中，由患者自己使用一次性传感器对疾病进行极其敏感的监测。

AbstractIntellectual MeritThis Sensor proposal focuses on the ability to detect small amounts of materials, including pathogenic bacteria and biomolecules integral to cell responses. New approaches are proposed to the problems of transducing mass changes and to the problems of on-chip multiplexing and demultiplexing. These ideas are based on concepts developed for advanced MEMS and integrated optic devices. Most current detection technologies are either, bulky, expensive or slow. We propose a novel device/instrument for ultra-sensitive detection of molecular amounts of material with applications in pathogen and biochemical detection, medicine, drug discovery, and nanotechnology. The proposed technology allows the detection of an array of different targets in an intrinsically networked structure through fiber-optically linked structures. The technology lends itself to high throughput at low cost through use of disposable passive chips.The device consists of a silicon-on-insulator based chip that incorporates ultra-sensitive nano-mechanical cantilevers with novel silicon-based passive integrated optics. Passive optical ring-resonators are used for on-chip wavelength multiplexing and demultiplexing of optical signals. The ring-resonators act as filters for different wavelengths, which are guided to different cantilever sensors. The cantilever waveguide is used for motion detection. Mechanical vibrations in the MHz range are encoded on the optical signal by one element of an array of biosensitized cantilever transducers. The one-to-one association of individual wavelengths with mechanical vibrations of different cantilever sensors allows one to address each sensing site. This innovation in transduction strategy allows the use of ring-resonators that do not need external tuning or closed-loop control. Furthermore, this strategy requires inexpensive broadband sources for optical carrier signals. The sensed shift in vibration frequency at each ring resonator/cantilever pair can be detected in parallel on the external device. The principle of operation of the biosensor is based on highly-sensitive, immunospecific attachment of pathogens to silicon nanofabricated structures. In addition to detecting its presence, the mass of the pathogen is also measured. Our preliminary results show that the cantilevers are able to detect mass in the attograms to picograms range. The additional information of the mass allows one to screen for false positives, greatly increasing the efficiency of the method. The IC compatible fabrication technology allows the cost to be truly minimized for the disposable chip. Emerging from this method is the possibility of high resolution measurements of the dry mass of a great variety of pathogens, from large unicellular organisms to viruses and large macromolecules. This novel Si-based nanophotonic motion detection scheme allows arrays of such devices to form a complete silicon platform for reduced cost, increased sensitivity and enormous system level integration revolutionizing functionality, cost and portability.Broader ImpactsThis research will will enable large scale accessibility for inexpensive compact tests, today only done in a few specialized laboratories. This will help prevent and diagnose diseases and bio hazardous materials of today. One could envision for example the detection of very small traces of hazardous chemicals used in biowarfare by a soldier in the field, carrying the sensor in his pocket, or extremely sensitive monitoring of a disease, in the doctor's office or at home, by the patient himself using a disposable sensor.