Analysis of μ-contact printed protein patterns by SPR imaging with a LED light source
Analysis of μ-contact printed protein patterns by SPR imaging with a LED light source
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DOI：
10.1021/la048177k
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发表时间：
2004-12-07
期刊：
影响因子：
3.9
通讯作者：
Cheng, Q
中科院分区：
文献类型：
--
作者：
Wilkop, T;Wang, ZZ;Cheng, Q
我们通过二维 (2-D) 表面等离子共振成像 (SPRi) 展示了 mu 接触印刷蛋白质图案的表征和蛋白质-蛋白质相互作用的分析。描述了采用发光二极管 (LED) 作为光源在 SPRi 图像质量方面的进步。我们证明 LED 提供了一种理想的点光源，可以消除使用激光源时发现的干扰伪影和斑点。固定角度成像可达到的厚度分辨率与单色源相当，为系统的定量分析提供了坚实的基础。这里报道的 SPR 成像技术提供亚纳米厚度灵敏度和微米横向分辨率，可以方便地研究生物分子相互作用和超薄膜的表面形态。使用聚二甲基硅氧烷（PDMS）印记在An上的功能化自组装单层上，通过微接触印刷获得了细菌毒素的空间明确的蛋白质模式。研究了着墨溶液中蛋白质浓度对转印效率的影响，并观察到溶液浓度与表面固定的蛋白质量之间存在非线性相关性。使用毒素特异性抗体对蛋白质相互作用进行定量分析，显示出浓度依赖性关系，验证了打印后蛋白质生物活性的保留。该研究证明了在 SPR 成像中使用 LED 作为光源的可行性和有效性，为开发紧凑型 SPR 仪器以直接、灵敏且无标记地检测生物危害分子打开了大门。
We demonstrate the characterization of mu-contact printed protein patterns and analysis of protein-protein interactions by two-dimensional (2-D) surface plasmon resonance imaging (SPRi). Advancements in SPRi image quality from employing a light emitting diode (LED) as the light source are described. We show that a LED offers an ideal point source that can eliminate interference artifacts and speckles found when using a laser source. The attainable thickness resolution in fixed-angle imaging is comparable to that of a monochromatic source, providing a solid foundation for quantitative analysis with the system. The SPR imaging technique reported here affords sub-nanometer thickness sensitivity and micrometer lateral resolution, allowing for convenient studies of biomolecular interactions and surface morphologies of ultrathin films. Spatially well-defined protein patterns of bacterial toxins were obtained by microcontact printing using a polydimethylsiloxane (PDMS) stamp on a functionalized self-assembled monolayer on An. The influence of protein concentration in the inking solution on transfer efficiency was investigated, and a nonlinear correlation was observed between the solution concentration and the amount of protein immobilized on the surface. Quantitative analysis of protein interaction was performed with toxin-specific antibody, showing a concentration-dependent relationship that verifies the retention of biological activity of the protein after printing. The study demonstrates the feasibility and effectiveness of using LEDs as light sources in SPR imaging, opening doors for developing compact SPR instruments for direct, sensitive, and label-free detection of biohazardous molecules.