SST: Novel Sensor Platforms Based on the Structural Integration of an Organic Light-Emitting Device, a Luminescent Sensing Element, and a Thin Film Si-Based Photodetector

这项提议的目标是开发完全结构集成的基于光致发光(PL)的新型传感器：光源、传感元件、光电探测器(PD)和相关滤光片被制造在透明衬底上并背靠背地连接。因此，由此产生的传感器可以非常紧凑、坚固、选择性、快速、自主、耗电少、价格低廉。该提案的重点是感知氧气，这是医疗、环境、(生物)化学和食品监测的关键工具，以及炭疽杆菌毒素(炭疽杆菌)。中心概念是上述组件的新颖整体结构集成。光源是有机发光器件(OLED)像素的阵列。传感元件包括具有嵌入染料的多孔膜、其荧光选择性地对分析物敏感的表面固定化物种、或在溶液中具有识别元件的微流控通道/井。Pd和滤光片是氢化纳米晶Si、SiGe和/或碳化硅的多层薄膜。几何结构将是“背面探测”，即OLED和PD像素被制造在衬底的同一侧。首先制作了长通滤光片和PD像素的阵列，然后在PD像素之间的间隙中制作OLED。该传感元件被制造在单独的基板上，并附着到OLED/PD基板上。在整个装置中，电子电路(包括指令接收器和数据发送器)、读出器和电池将被放置在PD后面。因此，整个设备将是大约2.5“x5”x1“，比目前任何可用的传感器都要紧凑得多，成本更低。这项工作为基于PL的传感器提供了一个新的平台，可以进一步开发成多分析传感器微阵列。创新的元素是(I)所有传感器组件的完全集成，以及(Ii)利用微流控体系结构和为特定识别分子量身定做的薄膜/表面开发传感器元件，这将提高灵敏度并缩短响应时间。此外，OLED将在脉冲模式下运行，这将延长其寿命并产生可以忽略不计的热量，这对热敏识别元件和试剂至关重要。氧将通过光致发光寿命进行监测，从而消除了频繁校准的需要。将评估不同的方法来生成用于现实世界应用的坚固的传感器。氧传感器将基于氧敏感染料的荧光的动态猝灭，最初使用绿色OLED和铂八乙基卟啉(PtOEP)染料。我们将把传感器与嵌入固体薄膜的染料与染料溶液进行比较。炭疽传感器将基于炭疽致死因子对某些多肽的裂解。标记的多肽将在爱荷华州立大学(ISU)的蛋白质设施中合成，在裂解位点的两侧都有一个Forster共振能量转移供体和受体。上述两种试剂的传感器将是国土安全、医疗、环境、生物、食品/酿造和健康/安全等领域广泛应用的理想选择。除了这些影响之外，这些设备还为化学和生物制剂定义了一个新的传感器平台，这可能导致极其紧凑和廉价的多分析传感器微阵列。拟议的工作将作为这一平台发展的基础。它还将扩展嵌入/固定识别元件、传感器设计和传感器工程方面的基础知识。它还将产生广泛的教育影响，促进ISU跨学科生物物理学项目的发展，并培训学生凝聚态物理、电气工程、生物物理、化学和分子生物学。通过为研究生开发新的实验课程模块，将其与教学相结合。计划让包括少数族裔和妇女在内的本科生大量参与。

0428220ShinarThe objective of this proposal is to develop novel photoluminescence (PL)-based sensors that are fully structurally integrated: The light source, the sensing element, and the photodetector (PD) and associated filter, are fabricated on transparent substrates and attached back-to-back. The resulting sensors could therefore be extremely compact, robust, selective, fast, autonomous, consume little power, and inexpensive. The proposal focuses on sensing oxygen, a key tool in medical, environmental, (bio)chemical, and food monitoring, and Bacillus anthracis toxin (anthrax).The intellectual merit. The central concept is the novel total structural integration of the foregoing components. The light source is an array of organic light-emitting device (OLED) pixels. The sensing elements include porous films with an embedded dye, surface immobilized species whose PL is selectively analyte-sensitive, or microfluidic channels/wells with recognition elements in solution. The PD and filter are multilayer thin films of hydrogenated nanocrystalline Si, SiGe, and/or SiC. The geometry will be "back detection," i.e., the OLED and PD pixels are fabricated on the same side of the substrate. The array of long-pass filters and PD pixels is fabricated first, followed by the OLEDs in the gaps between the PD pixels. The sensing element is fabricated on a separate substrate and attached to the OLED/PD substrate. In the complete device, the electronic circuitry (including instruction receiver and data transmitter), readout, and battery will be positioned "behind" the PD. Hence the whole device would be ~2.5"x5"x1", far more compact and less costly than any sensors currently available. The work results in a new platform for PL-based sensors, which can be further developed to multianalyte sensor microarrays. Innovative elements are (i) the complete integration of all the sensor components, and (ii) the development of sensing elements utilizing microfluidic architectures and films/surfaces tailored for specific recognition molecules, which will enhance the sensitivity and shorten the response time. Moreover, the OLEDs will be operated in a pulsed mode, which will increase their lifetime and generate negligible heat, which is crucial for heat-sensitive recognition elements and agents. Oxygen will be monitored via the PL lifetime, thus eliminating the need for frequent calibration.Different approaches will be evaluated to generate robust sensors for real-world applications. The oxygen sensor will be based on the dynamical quenching of the PL of oxygen-sensitive dyes, initially with a green OLED and Pt octaethyl porphyrin (PtOEP) dye. We will compare the sensors with dyes embedded in solid films with dyes solutions. The anthrax sensor will be based on the cleavage of certain peptides by anthrax lethal factor. Labeled peptides will be synthesized at the Protein Facility of Iowa State University (ISU), with a Forster resonance energy transfer donor and acceptor on either side of the cleavage site.The broader impacts. The sensors for the two aforementioned agents will be ideal for a broad range of applications in areas such as homeland security, medical, environmental, biological, food/brewing, and health/safety. Beyond these impacts, the devices define a new sensor platform for chemical and biological agents, which could lead to extremely compact and inexpensive multianalyte sensor microarrays. The proposed work will serve as a basis for the development of this platform. It will also expand the basic knowledge in embedding/immobilizing recognition elements, sensor design, and sensor engineering. It will also have a broad educational impact, promoting the growth of the interdisciplinary biophysics program at ISU and training students in condensed matter physics, electrical engineering, biophysics, chemistry, and molecular biology. It will be integrated with teaching by developing new experimental course modules for graduate students. Significant participation of undergraduates, including minorities and women, is planned.