A label-free optical sensor system on silicon: Determining the thermodynamic and kinetic quantities of protein-ligand interactions

光学无标签生物传感器采用自由空间光学，如表面等离子体共振装置已成功进入市场。同时，无光学标签生物传感的芯片集成解决方案具有许多优点，如显着减小尺寸，在小芯片上实现大量传感器元件，高度并行操作以及对生物材料的需求最小。在本提案中，多学科方法汇集了硅光子学，化学和生物化学方面的专业知识。总体目标是开发一种基于硅的光学生物传感器系统，用于高度并行的分析和必要的化学，以获得一个真实世界的生物传感器系统，用于并行实时测量几种生物蛋白质-配体相互作用。Petermann/Bruns团队带来了他们在硅光子学方面的知识，r<s:1> ck- braun团队带来了硅表面化学（包括分析）方面的专业知识，Volkmer团队带来了生物模型，生物传感器可以在生物模型上进行优化和广泛测试。传感器本身将在SOI（绝缘体上硅）中实现。我们将环形谐振器作为传感元件与基于热光调制的大规模并行传感新方法相结合。为了使传感器的适用性最大化，将开发一种用于大动态传感的新结构。此外，为了实现我们应用的最佳解决方案，传感器结构的几种变化，如波导类型和环形状将被执行。在生化方面，已建立的硅表面化学和描述良好的蛋白质配体相互作用将用于功能化和验证传感器系统。使用微流体，平行定量亲和测量的生物相互作用的调查将被执行。将建立温度相关测量来确定热力学参数，如吉布斯自由能、焓、熵和反应活化能。最后，非常具有挑战性的测定蛋白质-蛋白质相互作用的化学计量学将被研究。我们将尝试使用我们的无标记生物传感器系统来确定蛋白质复合物的低聚状态。这种生物传感器系统将使我们有可能通过一次实验来确定蛋白质-配体相互作用的热力学、动力学和化学计量参数。

Optical label-free biosensors using free-space optics like surface plasmon resonance devices have successfully entered the market. Meanwhile it becomes clear that chip-integrated solutions for optical label-free biosensing feature many advantages like significant size reduction enabling a large number of sensor elements on a small chip, highly parallel operation and a minimal demand of biomaterial. In this proposal a multidisciplinary approach brings together the expertise in silicon photonics, chemistry and biochemistry. The overall goal is to develop a silicon based optical biosensor system for highly parallel assays and the necessary chemistry to get a real world biosensor system for parallel real time measurements of several kinds of biological protein-ligand interactions.The group of Petermann/Bruns brings in their knowledge on silicon photonics, the group of Rück-Braun the expertise on silicon surface chemistry including analysis, and the group of Volkmer brings in the biological models on which the biosensor can be optimized and tested extensively.The sensor itself will be realized in SOI (silicon-on-insulator). We combine well known ring resonators as sensing elements with a new approach for massive parallel sensing based on thermo-optical modulation. To maximize the applicability of the sensor, a new structure for large dynamic sensing will be developed. Furthermore, to achieve the best solution for our applications, several variations of the sensor structure like waveguide type and ring shape will be performed.On the biochemical side, established silicon surface chemistry and well described protein-ligand interactions will be used to functionalize and verify the sensor system.Using microfluidics, parallel quantitative affinity measurements of the biological interactions under investigation will be performed. Temperature dependent measurements will be established to determine the thermodynamic parameters such as Gibbs free energy, enthalpy, entropy and reaction activation energy. Finally, the very challenging determination of the protein-protein interaction stoichiometry will be investigated. We will try to determine the oligomeric state of a protein complex using our label-free biosensor system. This biosensor system will give us the possibility to determine the thermodynamic, kinetic and stoichiometric parameters of protein-ligand interactions with a single experimental run.