Development of a high-resolution scanning electrochemical microscope to characterize micro-bio devices

我们开发了一种高分辨率扫描电化学显微镜(SECM)来表征各种微型生物器件。我们基于SECM的多功能测量系统通过光纤电极探头提供近场扫描光学显微镜(NSOM)信息。电极、光纤或光纤电极探头的尺寸小于100 nm，这使得我们能够获得蛋白质阵列和细胞阵列的高分辨率图像。利用剪切力控制探针-样品距离的反馈机制，获得了生理条件下高度差大于10μm的粗糙表面和活细胞等脆性样品的高质量图像。1.采用Ti/P溅射和随后的对二甲苯C气相沉积聚合法制备了纳米电极探针。由循环伏安曲线估算的亚铁氰化物的有效电极半径小于50 nm。光学f-…用同样的方法制作了更多半径小于100 nm的Iber电极探针。从直径为数十nm的量子点(QD)粒子的非自组织光学显微镜(NSOM)图像的横截面上可以看出，其光学孔径也小于100 nm。2.通过垂直移动宽度为~100 nm的探头，改进了控制探头-样品距离的反馈机制，减少了对样品的损伤。这种反馈模式被定义为“站立方法(STA)模式”(Yamada等人，anal.化学，2005，77,1785-179)，首次实现了生理条件下单个PC-12细胞轴突和细胞体的同时电化学和地形图图像。对于商用的原子力显微镜，STA模式的反馈成像有时比针尖样品调节效果更好。例如，相对较大的聚苯乙烯小球(直径约10μm)可以用我们的STA型扫描电子显微镜成像，而不是用传统的原子力显微镜仪器成像。尤其是胶原胶包埋培养的细菌和哺乳动物细胞，体积极小(几十到几个毫升)，已经被成功地展示在玻璃或硅芯片上，用于微制造各种类型的细胞阵列。微接触印刷(μCP)、微流控技术、浸渍笔纳米光刻(DPN)和负电介质电泳(n-DEP)也被应用于组装蛋白质和细胞阵列。较少

We developed a high-resolution scanning electrochemical microscope (SECM) towards characterization of various micro-bio devices. Our SECM-based multifunctional measuring system provides near-field scanning optical microscopic (NSOM) information by featuring an optical fiber-electrode probe. The size of the electrode-, optical fiber-, or optical fiber-electrode- probe is less than 100nm, which allows us high-resolution images of protein arrays and cellular arrays. The feedback mechanism controlling the probe-sample distance is based on the shearing force, by which high-quality images of rough surfaces with the height differences larger than 10μm and fragile samples such as living cells under physiological conditions were captured.1, Nano-electrode probes were fabricated with the Ti/P sputtering and the subsequent parylene C-vapor deposition polymerization. The effective electrode radius estimated from the cyclic voltammogram for ferrocyanide has found to be less than 50nm. The optical f … More iber-electrode probes with the radii less than 100nm were made as the same manner. The optical aperture size was also less than 100 nm which was confirmed from the cross section of the NSOM image of the quantum-dot (QD) particles with tens nm-diameters.2, The feedback mechanism controlling the probe-sample distance was improved by vertically moving the probe with the width of 〜 100nm to reduce the damage applied to the samples. This feedback mode, defined as "standing approach (STA) mode" (Yamada et al., Anal. Chem., 2005, 77, 1785-179), has allowed to simultaneous electrochemical and topographic images of the axon and the cell body of the single PC-12 cell under physiological conditions for the first time. The STA-mode feedback imaging sometimes works better than the tip-sample regulation for the commercially available AFM. For example, relatively larger polystyrene beads (with 〜 10μm diameter) can be imaged with our STA-mode SECM, whereas not imaged with the conventional AFM instrument.3, Towards the progress in the construction of the micro-bio devices, various techniques to pattern baiomaterials were attempted. Especially, collagen-gel embedded culture of bacteria and mammalian cells with ultra-small volume (tens to several nL) has been successfully demonstrated on glass or silicon chip to microfabricate various types of cellular arrays. Micro-contact printing (μCP), microfluidics, dip-pen nanolithography (DPN), and negative dielectric phoresis (n-DEP) have been also applied to assemble protein and cellular arrays. Less