NER: Chemical Probing of Biosensor Nano-environments using Dynamic AFM

NER：使用动态 AFM 对生物传感器纳米环境进行化学探测

• 批准号: 0210205
• 负责人: James Schneider
• 金额: $ 10万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0210205&HistoricalAwards=false
• 关键词: NER; Chemical; Probing; Biosensor; Nano

Biosensors are becoming increasingly important for genomic analysis, detection of warfare agents, and medical diagnostics. To optimize the performance of these devices, new tools must be developed to characterize the molecular-level phenomena that underlie their function. This exploratory nanotechnology proposal aims to develop a new method to measure nanoscopic properties of biosensor surfaces, utilizing the ultrafine resolution of atomic force microscopy (AFM) in dynamic mode.Biosensors must perform two functions at once. They must encourage the binding of specific analytes while discouraging the binding of adventitious material. Typically, these goals are achieved by building heterogeneous surfaces with antifouling polymers together with receptors specific for desired analytes. To maximize yield without sacrificing selectivity, an optimal density and thickness of polymer must be applied to the surface. In this work, the PI hopes to measure the nanoscopic energy landscape that a biomolecule traverses near the sensor surface in an attempt to guide the rational design of biosensors. For a realistic measurement, both polymer steric interactions and specific ligand-receptor interactions must be measured simultaneously.The dynamic AFM method involves oscillating the AFM cantilever and measuring the amplitude attenuation as the sample approaches the AFM tip. Amplitude attenuation is more sensitive to polymer steric forces than deflection, so the sharp tips required for specific ligand-receptor measurements can be used. Here, the PI will measure dynamic and conventional AFM force curves in a model biosensor system. Using a theoretical description of cantilever oscillation, we hope to demonstrate the sensitivity and accuracy of the dynamic method.If successful, the project will have an impact on many fronts. First, the technique will provide a unique nanoscopic probe of heterogeneous surfaces pertinent to biosensors. It will also be able to measure polymer steric forces with nanometer lateral resolution, with implications for lubrication and colloidal processing. Finally, since epithelial and bacterial cell surfaces also contain specific adhesion receptors together in a polymeric environment, the dynamic AFM force method may emerge as a powerful tool in the study of cell-cell and cell-surface adhesion.

生物传感器对于基因组分析，战争剂的检测和医学诊断越来越重要。为了优化这些设备的性能，必须开发新工具以表征其功能构成的分子级现象。该探索性纳米技术建议旨在开发一种新方法来测量生物传感器表面的纳米镜头特性，利用动态模式下的原子力显微镜（AFM）的超细分辨率分辨率。BIOSENSORS必须一次执行两个功能。他们必须鼓励特定分析物的结合，同时劝阻不定材料的结合。通常，这些目标是通过用防扰聚合物以及所需分析物特异性的受体来建立异质表面来实现的。为了最大程度地提高产量而无需牺牲选择性，必须将最佳密度和聚合物的厚度应用于表面。在这项工作中，PI希望测量生物分子在传感器表面附近遍历的纳米能量景观，以指导生物传感器的合理设计。为了进行现实的测量，必须同时测量聚合物空间相互作用和特定的配体 - 受体相互作用。动态AFM方法涉及振荡AFM悬臂振荡并在样品接近AFM尖端时测量振幅衰减。振幅衰减比偏转对聚合物空间力更敏感，因此可以使用特定配体受体测量所需的清晰尖端。在这里，PI将测量模型生物传感器系统中的动态和常规AFM力曲线。使用悬臂振荡的理论描述，我们希望证明动态方法的敏感性和准确性。如果成功，该项目将对许多方面产生影响。首先，该技术将提供与生物传感器相关的异质表面的独特纳米探针。它还能够用纳米横向分辨率测量聚合物空间力，这对润滑和胶体处理的影响。最后，由于上皮和细菌细胞表面在聚合物环境中还包含特定的粘附受体，因此动态AFM力法可能会成为细胞细胞和细胞表面粘附研究的强大工具。