Development of the Scanning Electrochemical Microscope for Biological Imaging

扫描电化学显微镜（SECM）是一种扫描探针显微镜，具有对表面形貌和化学性质进行成像的独特能力。SECM主要用于检查无生命的物体，但由于其监测化学分泌和检查形态的潜力，在生物研究中具有很大的前景。事实上，BioSECM将用于成像地形和探测活细胞的化学成分。一个由两名化学家和一名生物学家组成的团队将联手开发一种用于生物样品的新型扫描电化学显微镜。新的BioSECM将结合其他现有显微镜所没有的特征。它的作用是构建活细胞表面的三维图像，同时生成细胞表面选定化学过程的敏感地图和时间分辨分析。这种扫描显微镜的独特之处在于能够以低于1毫米的横向分辨率观察到大至1000,1000,20mm （l, w, h）的特征，并将地形和化学图像相关联，以检测伴随细胞分泌变化的形态学变化。该显微镜将包含商业仪器所不具备的功能，例如通过使用剪切力或阻抗模式反馈控制器在恒定分离时对表面成像的能力，以及通过使用伏安、安培或电位尖端获取化学信息的能力。将开发适用于从样品表面释放的生物重要分子的安培和伏安检测的探针。如果使用成像探针干扰或破坏活样品，则BioSECM的效用将被最小化。因此，将开发成像方法以避免对样品的损坏。另外，该探针可以通过在样品表面附近短暂地产生有毒化学物质来有意地改变或破坏生物结构。BioSECM成像活细胞的能力将通过检测PC12细胞来测试，PC12细胞是一种用于模拟神经元功能许多方面的细胞系。BioSECM将推进培养活细胞的生物学研究。在短期内，BioSECM将成为研究神经细胞生长和死亡的宝贵工具，可以同时监测神经细胞的形态变化和神经递质释放。此外，BioSECM将在许多其他生物学相关领域发挥作用。例如，检查医学和牙科植入物上生物诱导的腐蚀过程和生物膜的能力将进一步推动金属腐蚀研究。由于可以同时测量细胞形态和化学环境的变化，BioSECM也将成为研究神经元退化的宝贵工具。此外，人们认为，整个SECM成像社区将欣赏BioSECM的技术进步，预计其他研究人员将建立一个或作为商业设备的基础。

AbstractDEVELOPMENT OF THE SCANNING ELECTROCHEMICAL MICROSCOPE FOR BIOLOGICAL IMAGINGThe scanning electrochemical microscope (SECM) is a scanned-probe microscope with the unique ability to image both the topography and chemistry of a surface. The SECM has been used primarily to examine inanimate objects but, with its potential for monitoring chemical secretion and examining morphology, holds great promise in biological investigations. Indeed, the BioSECM will be used to image the topography and probe the chemistry of living cells.A team of two chemists and a biologist will join forces to develop a new scanning electrochemical microscope for use with biological samples. The new BioSECM will have a combination of features not found in other existing microscopes. Its role is to construct 3-d images of the surfaces of living cells while simultaneously producing sensitive maps and time-resolved analysis of selected chemical processes at the surface of the cells. Unique to this scanning microscope is the ability to observe features as large as 1000 , 1000 , 20 mm (l , w, h) with lateral resolution below 1 mm and to correlate topographic and chemical images for detection of morphological changes accompanying changes in cell secretion. The microscope will incorporate features not available in commercial instruments such as the ability to image surfaces at constant-separation by use of shear-force or impedance mode feedback controllers and the ability to acquire chemical information by employing voltammetric, amperometric, or potentiometric tips. Probes will be developed that are suitable for amperometric and voltammetric detection of biologically important molecules released from sample surfaces. The utility of the BioSECM is minimized if use of an imaging probe perturbs or destroys a living sample. Thus, imaging methods will be developed to avoid damage to samples. Alternately, the probe can be used to intentionally alter or destroy biological structures by transiently generating toxic chemicals near sample surfaces. The ability of the BioSECM to image living cells will be tested by using it to examine PC12 cells, a cell line used to model many aspects of neuron function.The BioSECM will advance biological investigations of cultured living cells. In the near term, the BioSECM will be an invaluable tool for investigations into nerve cell growth and death by allowing changes in morphology and neurotransmitter release to be simultaneously monitored. Additionally, the BioSECM will be useful in many other biologically relevant areas. For example, metallic corrosion investigations will be furthered by the ability to examine biologically induced corrosion processes and biofilms on medical and dental implants. BioSECM will also be an invaluable tool for investigations into neuron degeneration, as changes in cell morphology and chemical environment can be simultaneously measured. Moreover, it is felt that the SECM imaging community at large will appreciate the technological advances of the BioSECM and it is anticipated that other investigators will build one or be the basis of a commercial device.