Atomic force microscope for high resolution imaging and force spectrometry with chemical specificity

原子力显微镜(AFM)是一种成像方法，通过将安装在悬臂上的尖端在样品表面进行栅格扫描。当尖端在样品上移动时，它所经历的粘附力或排斥力将导致悬臂上下偏转。这可以转化为尖端所经过的表面的“地图”，从而形成样品的三维地形图像。AFM的图像分辨率比标准光学显微镜高得多，只有10纳米大小的特征--即原子大小的大约50倍--通常被解决。这笔赠款是为了升级现有的原子力显微镜系统。目前的AFM装置大约有八年的历史。在扫描仪和探测器装置保持良好的情况下，电子控制模块和操作软件不再是最先进的。但由于我们目前有两个扫描仪装置在运行，新的控制模块将允许我们以一个的价格运行两个AFM系统，新系统致力于绘制具有高化学特异性的表面官能团的图谱。新的AFM系统将由皇后大学化学系的五名研究人员使用。升级后的系统将允许我们获得软样品的高分辨率图像，如聚合物、胶体颗粒的表面以及嫁接到这些表面上的蛋白质或多肽的表面。此外，升级后的系统将允许在水下对样品进行成像，这在这种情况下尤其重要由于许多正在研究的化学系统涉及与水接触的固定在固体表面上的分子。对正在研究的材料的高分辨率成像对于了解它们的化学反应至关重要，因为对反应至关重要的分子的吸附通常只在表面上独特的、分布广泛的位置发生。新设备将使我们能够表征用于新的分离和检测技术的材料，包括检测环境传感器中的痕量重金属；检测和表征廉价的一次性医疗设备中的蛋白质和多肽；以及使用手性层析分离药物分子。

Atomic force microscopy (AFM) is an imaging method whereby a sharp tip mounted on a cantilever is rastered over the surface of a sample.  As the tip travels over the sample, the adhesive or repulsive forces that it experiences will result in the deflection of the cantilever up and down.  This can be translated into a "map" of the surface the tip is traveling across, and thus into a three-dimensional topographic image of the sample.  The image resolution in AFM is much higher than a standard optical microscope, with features only 10 nanometers in size - i.e. some 50 times the size of an atom - being routinely resolved.  This grant is for the upgrade of an existing AFM system. The current AFM unit is about eight years old.  While the scanner and detector units remain in good condition, the electronic control modules and operating software are no longer state-of-the-art.  As we currently have two scanner units in operation, the new control module will allow us to run two AFM systems for the price of one, with the new system being dedicated to mapping of surface functional groups with high chemical specificity.  The new AFM system will be used by a group of five researchers within the chemistry department at Queen's University.  The upgraded system will allow us acquire high-resolution images of soft samples such as the surfaces of polymers, colloidal particles and of proteins or peptides that are grafted onto such surfaces.  In addition, the upgraded system will allow for imaging of the samples under water, which is particularly important in this case, as many of the chemical systems under study involve molecules immobilized on a solid surface in contact with water.  High resolution imaging of the materials under study is crucial in understanding their chemical reactivity as often adsorption of molecules critical to a reaction will only take place at unique, widely spaced sites on the surface.  The new equipment will allow us to characterize the materials used in novel separation and detection technologies, including the detection of trace quantities of heavy metals in environmental sensors; the detection and characterization of proteins and peptides in cheap, disposable medical devices; and the separation of drug molecules using chiral chromatography.