Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.
ACS Nano. 2013 Jan 22;7(1):689-94. doi: 10.1021/nn3050598. Epub 2012 Dec 24.
Ion current through a single-walled carbon nanotube (SWCNT) was monitored at the same time as fluorescence was recorded from charged dye molecules translocating through the SWCNT. Fluorescence bursts generally follow ion current peaks with a delay time consistent with diffusion from the end of the SWCNT to the fluorescence collection point. The fluorescence amplitude distribution of the bursts is consistent with single-molecule signals. Thus each peak in the ion current flowing through the SWCNT is associated with the translocation of a single molecule. Ion current peaks (as opposed to blockades) were produced by both positively (Rhodamine 6G) and negatively (Alexa 546) charged molecules, showing that the charge filtering responsible for the current bursts is caused by the molecules themselves.
当通过单壁碳纳米管 (SWCNT) 的离子电流与通过 SWCNT 迁移的带电染料分子的荧光同时被监测时，离子电流通常会跟随荧光爆发，延迟时间与从 SWCNT 末端到荧光收集点的扩散一致。爆发的荧光幅度分布与单分子信号一致。因此，流过 SWCNT 的离子电流中的每个峰值都与单个分子的转位相关。正电荷（若丹明 6G）和负电荷（Alexa 546）分子都产生了离子电流峰值（而非阻塞），表明导致电流爆发的电荷过滤是由分子本身引起的。
