SGER: Protein Interactions with Nano-Scale Controlled Surfaces: Non-Fouling Mechanism

姜绍义，华盛顿“SGER：蛋白质与纳米级控制表面的相互作用：无污垢机制。”无污垢表面对生物传感器和生物材料的性能至关重要。尽管它们的重要性和巨大的努力，但目前不结垢机理仍不清楚。许多实验仍然无法解释，许多有争议的问题仍然没有解决。已有几种模型试图阐明不结垢机理。然而，缺乏一个统一的模型（或假设）来解释各种实验，并确定无污垢表面的起源。在一些理论研究中，要么不包括蛋白质分子，要么使用连续介质简化的蛋白质模型。这项工作的新颖之处在于它的假设，即表面的纳米级结构负责蛋白质的吸附/抵抗，以及它的综合实验和模拟方法旨在证明这一假设。在本研究中，通过在不同温度下形成聚乙二醇（PEG）端自组装单层膜（sam）或通过调整混合PEG和OH端自组装单层膜的组成，可以改变其状态（例如，液态结晶或非晶体）。蛋白质在这些表面上的吸附将使用表面等离子体共振（SPR）生物传感器进行测量。原子力显微镜(AFM)/扫描隧道显微镜（STM）、x射线光电子能谱（XPS）、傅里叶变换红外光谱-衰减全反射（FTIR-ATR）和和频生成（SFG）将用于表征这些SAMs和吸附的水分子。同时，将进行分子模拟，通过计算蛋白质吸附时的自由能变化和检查SAM表面附近的吸附水结构，研究纳米级SAM结构如何影响蛋白质的吸附/阻力。这项工作的成功将促进对蛋白质在界面上行为的基本理解，并为设计更好的生物传感器和生物材料提供指导。它将满足从国土安全到环境监测到生物医学应用等许多领域对化学和生物物质的检测和鉴定的迫切需要。

Shaoyi JiangU of Washington"SGER: Protein Interactions with Nano-Scale Controlled Surfaces: Non-Fouling Mechanism."Non-fouling surfaces are critical to the performance of biosensors and biomaterials.Despite of their importance and enormous effort, non-fouling mechanism is still unknown at present. Many experiments remain unexplained and many controversial issues remain unresolved. There exist several models attempted to elucidate non-fouling mechanism. However, there is a lack of a unified model (or hypothesis), which can explain various experiments and identify the origin of non-fouling surfaces. Among several theoretical studies, either protein molecules are not included, or simplified protein models with continuum medium are used. The novelty of this proposed work is its hypothesis that nano-scale structures of a surface are responsible for protein adsorption/resistance and its integrated experimental and simulation approach designed to prove the hypothesis. In the proposed work, the state (e.g., ieliquid crystalli or ircrystall.) of polyethylene glycol (PEG) terminated self-assembled monolayers (SAMs) will be altered by forming the SAMs at different temperatures or by adjusting the composition of mixed PEG and OH terminated SAMs. Protein adsorption on these surfaces will be measured using surface plasmon resonance (SPR) biosensors. Atomic force microscopy (AFM)/scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), Fourier transform IR spectroscopy-attenuated total reflection (FTIR-ATR), and sum frequency generation (SFG) will be used to characterize these SAMs and adsorbed water molecules. In parallel, molecular simulations will be performed to study how protein adsorption/resistance is affected by nano-scale SAM structures by calculating free energy change upon protein adsorption and examining adsorbed water structure near SAM surfaces. The success of this work will advance the fundamental understanding of protein behavior at interfaces and provide a guide to design better biosensors and biomaterials. It will meet the urgent need for the detection and identification of chemical and biological substances in many areas from homeland security to environmental monitoring to biomedical applications.