Analytische Chemie - Elektroanalytik & Sensorik, Ruhr-University Bochum, D-44780 Bochum, Germany.
Anal Chem. 2010 Jul 1;82(13):5900-5. doi: 10.1021/ac100738b.
Carbon fiber nanoelectrodes with nanometer radii tip curvatures were fabricated using a shearforce-based constant-distance scanning electrochemical microscope and electrochemically induced polymer deposition. A simple DC etching procedure in alkaline solution provided conically sharpened single carbon fibers with well-formed nanocones at their bottom. Coating the stems but not the end of the tips of the tapered structures with anodic electrodeposition paint was the strategy for limiting the bare carbon to the foremost end and restricting a feasible voltammetry current response to exactly this section. The electrodeposition of the polymer was prevented at the foremost end of the tip using a shearforce-based tip-to-sample distance control that allowed approaching the etched tips carefully in just touching distance to a film of a silicone elastomer. Analysis of the steady-state cyclic voltammograms in presence of a reversible redox compound revealed effective radii for the obtained needle-type carbon-fiber nanoelectrodes down to as small as 46 nm. The method offers an alternative pathway toward the fabrication of highly miniaturized carbon electrodes.
使用基于剪切力的恒距扫描电化学显微镜和电化学诱导聚合物沉积，制备了具有纳米半径尖端曲率的碳纤维纳米电极。在碱性溶液中进行简单的直流蚀刻程序，可提供具有圆锥形尖锐度的单根碳纤维，并在其底部形成形状良好的纳米锥。在锥形结构的茎部但不在尖端涂覆阳极电泳漆是将裸露的碳纤维限制在最前端并将可行的伏安响应限制在该部分的策略。使用基于剪切力的尖端到样品距离控制来防止聚合物在尖端的最前端沉积，该控制允许小心地将蚀刻尖端靠近硅酮弹性体薄膜接触距离，以接近硅酮弹性体薄膜。在存在可逆氧化还原化合物的情况下对稳态循环伏安法进行分析，结果表明，所获得的针型碳纤维纳米电极的有效半径小至 46nm。该方法为制造高度微型化的碳电极提供了另一种途径。
