Scanning Electrochemical Microscopy of Individual Single-Walled Carbon Nanotubes

作者：Kim Jiyeon; Xiong Hui; Hofmann Mario; Kong Jing; Amemiya Shigeru^*

来源：Analytical Chemistry, 2010, 82(5): 1605-1607.

DOI：10.1021/ac9028032

Here we report on the novel application of scanning electrochemical microscopy (SECM) to enable spatially resolved electrochemical characterization of individual single-walled carbon nanotubes (SWNTs). The feedback imaging mode of SECM was employed to detect a pristine SWNT (similar to 1.6 nm in diameter and similar to 2 mm in length) grown horizontally on a SiO(2) surface by chemical vapor deposition. ne resulting image demonstrates that the individual nanotube under an unbiased condition is highly active for the redox reaction of ferrocenylmethyltrimethylammonium used as a mediator. Micrometer-scale resolution of the image is determined by the diameter of a disk-shaped SECM probe rather than by the nanotube diameter as assessed using 1.5 and 10 pm diameter probes. Interestingly, the long SWNT is readily detectable using the larger probe although the active SWNT covers only similar to 0.05% of the insulating surface just under the tip. This high sensitivity of the SECM feedback method is ascribed to efficient mass transport and facile electron transfer at the individual SWNT.

• 出版日期2010-3-1