Department of Chemistry, Faculty of Science, Hokkaido University , Sapporo, Hokkaido 060-0810, Japan.
Department of Mechanical Engineering, The University of Tokyo , Bunkyo-ku, Tokyo 113-8656, Japan.
ACS Appl Mater Interfaces. 2017 Nov 8;9(44):38992-38998. doi: 10.1021/acsami.7b07636. Epub 2017 Oct 24.
Local surface plasmon resonance (LSPR)-induced oxidation of semiconducting and metallic single-walled nanotubes (SWNTs) on the nanometer scale was investigated using surface-enhanced Raman scattering (SERS) measurements. An isolated SWNT was supported on a well-defined Au nanodimer structure that possesses an LSPR field at the nanogap under light irradiation, and highly intense SERS spectra of the SWNT at the gap region were measured. SERS analysis under O-saturated solutions and the addition of reactive oxygen species inhibitors demonstrated that condensed singlet oxygen (O), which is one of the reactive oxygen species, was efficiently generated from a semiconducting SWNT at the nanogap by the LSPR field and led to the local oxidation of the tube. In contrast to the semiconducting SWNT, no defect formation was observed in a metallic SWNT, probably because of rapid quenching of the photoexcited state. This selective local defect formation by LSPR-induced oxidation of a semiconducting SWNT would provide novel nanoprocessing and nanofunctionalization methods for the fabrication of future SWNT-based nanodevices.
使用表面增强拉曼散射 (SERS) 测量研究了局域表面等离子体共振 (LSPR) 在纳米尺度上诱导半导体和金属单壁纳米管 (SWNT) 的氧化。孤立的 SWNT 支撑在具有 LSPR 场的明确定义的 Au 纳米二聚体结构上，该结构在光照射下在纳米间隙中具有 LSPR 场，并且在间隙区域测量到 SWNT 的高度强烈的 SERS 光谱。在 O2 饱和溶液和添加活性氧物种抑制剂下的 SERS 分析表明，凝聚的单线态氧 (O)，它是活性氧物种之一，通过 LSPR 场从半导体 SWNT 在纳米间隙中有效产生，并导致管的局部氧化。与半导体 SWNT 相比，在金属 SWNT 中未观察到缺陷形成，这可能是由于光激发态的快速猝灭。这种通过 LSPR 诱导的半导体 SWNT 局部缺陷形成将为制造未来基于 SWNT 的纳米器件提供新的纳米加工和纳米功能化方法。
