Electro-Optically Modulated SPR: Densely Multiplexed High-Sensitivity Biosensor

描述（由申请人提供）：该快速通道项目的总体目标是开发基于一种技术的产品，该技术从根本上改变了成熟的生物传感器技术-表面等离子体共振（SPR）-的使用方式。这种新方法有可能大大提高SPR药物发现的通量，并可能导致创建实用的手持SPR生物传感器。阶段I将表明，通过添加具有电子控制折射率的额外层来修改常规SPR“堆叠”，从而创建了一种结构，在该结构中，即使分析物结合改变了堆叠顶部的折射率，也可以以固定角度检测等离子体共振。这解决了困扰SPR生物传感器超过20年的问题：基于角度的测量与高斑点计数（100或1,000）生物芯片的SPR成像的根本不兼容性。第一阶段还将证明，通过施加随时间变化的电压的电光（E-O）层，从而调制共振条件，同步检测生物分子结合使用SPR。这也代表了一个重大的进步，因为它将使各种各样的灵敏度增强技术的就业迄今不可能的，或非常不切实际的，使用其他SPR检测方法。第二阶段将建立在第一阶段的基础上，展示指数调制表面等离子体共振（MSPR）检测的基本优势。这一阶段将最终创建和表征一个完整的系统，同时从单个芯片上的数百个生物识别位点产生实时SPR传感图。这将通过将芯片表面成像到CMOS检测器阵列上并快速扫描E-O层的索引来实现。当E-O层的指数达到一个值时，“堆栈”与生物点一起达到共振，该点的图像将消失。通过记录特定光斑图像消失时的偏置电压，可以明确地确定其折射率。因此，每次扫描MSPR阵列的E-O层时，将创建表面上的折射率的完整图像。因为不需要“角度扇出”来检测共振，生物识别点可以非常紧密地堆积在表面上-几乎与基于标记的系统相同的密度。在扫描期间“抖动”E-O偏置电压将具有直接在结合位点处调制共振条件的效果，从而允许使用“锁定”检测，这可以潜在地将双折射率灵敏度增加一个数量级或更多，超过已经令人印象深刻的？通过商业Biacore装置实现n < 10-7。

DESCRIPTION (provided by applicant): The overall objective of this Fast Track project is to develop products based on a technique that radically alters the way a mature biosensor technology - surface plasmon resonance (SPR) - is used. This new approach has the potential to dramatically improve SPR throughput for drug discovery, and could lead to the creation of practical hand-held SPR biosensors. Phase I will show that modifying the conventional SPR "stack" by adding an extra layer with an electronically controlled refractive index creates a structure in which plasmon resonance can be detected at a fixed angle, even as analyte binding changes the refractive index at the top of the stack. This solves a problem that has bedeviled SPR biosensors for more than 20 years: the fundamental incompatibility of angle-based measurement with SPR imaging of high spot-count (100's or 1,000's) biochips. Phase I will also demonstrate, by applying a time-varying voltage to the electro-optic (E-O) layer, and thereby modulating the resonance condition, synchronous detection of biomolecular binding using SPR. This also represents a significant advance, since it will enable the employment of a wide variety of sensitivity-enhancing techniques hitherto impossible, or extremely impractical, using other SPR detection approaches. Phase II will build on the Phase I demonstration of the fundamental advantages of index-modulated surface plasmon resonance (MSPR) detection. This phase will culminate in the creation and characterization of a complete system that produces real-time SPR sensograms from hundreds of biorecognition sites on a single chip simultaneously. This will be achieved by imaging the surface of the chip onto a CMOS detector array and rapidly scanning the index of the E-O layer. When the E-O layer's index gets to a value for which the "stack" together with a biospot reaches resonance, the image of that spot will disappear. By recording the bias voltage at which a particular spot's image disappears, its refractive index can be unambiguously determined. Thus, each time the MSPR array's E-O layer is swept, a complete image of the refractive index on the surface will be created. Because no "angular fan-out" is required to detect resonance, biorecognition spots can be packed very closely on the surface -virtually at the same density as for label-based systems. "Dithering" the E-O bias voltage during the sweep will have the effect of modulating the resonance condition directly at the binding site, allowing the use of "lock-in" detection, which can potentially increase refractiv index sensitivity by an order of magnitude or more over the already-impressive ?n < 10-7 achieved by the commercial Biacore device.