Pancakes in tubes: Coronenes, a class of planar π‐conjugated molecules, organize in 1D structures when using single‐walled carbon nanotubes (SWCNTs) as templates (see picture). Coronene columns with coaxial stacking in SWCNTs exhibit characteristic fluorescence spectra that significantly differ from those of isolated coronene molecules and three‐dimensional crystals and that are related to their well‐ordered 1D structure.

We have investigated the growth mechanism of coronene-derived graphene nanoribbons (GNRs) using two different precursors: coronene and a dimer form of coronene, so-called dicoronylene (C48H20). For both of the precursors, the formation of nanoribbon-like materials inside carbon nanotubes (CNTs) was confirmed by transmission electron microscope observations. Experimental and theoretical Raman analysis reveals that the samples also encapsulated dicoronylene and linearly condensed other coronene oligomers, which can be regarded as analogues to GNRs. Interestingly, it was found that the present doping condition of coronene yields dicoronylene prior to encapsulation due to the thermal dimerization of coronene. These results indicate that the dimerization before the encapsulation drives the preferential formation of the coronene-based GNRs within CNTs.

Electrode-embedded nanopore is considered as a promising device structure for label-free single-molecule sequencing, the principle of which is based on nucleotide identification via transverse electron tunnelling current flowing through a DNA translocating through the pore. Yet, fabrication of a molecular-scale electrode-nanopore detector has been a formidable task that requires atomic-level alignment of a few nanometer sized pore and an electrode gap. Here, we report single-molecule detection using a nucleotide-sized sensing electrode embedded in-plane nanopore. We developed a self-alignment technique to form a nanopore-nanoelectrode solid-state device consisting of a sub-nanometer scale electrode gap in a 15 nm-sized SiO2 pore. We demonstrate single-molecule counting of nucleotide-sized metal-encapsulated fullerenes in a liquid using the electrode-integrated nanopore sensor. We also performed electrical identification of nucleobases in a DNA oligomer, thereby suggesting the potential use of this synthetic electrode-in-nanopore as a platform for electrical DNA sequencing.

Chemical modification of carbon nanotube surface can controllably modulate their optical properties. Here we report a simple and effective synthesis method of oxygen-doped single-walled carbon nanotubes (o-SWCNTs), in which a thin film of SWCNTs is just irradiated under the UV light for a few minutes in air. By using this method, the epoxide-type oxygen-adducts (ep-SWCNTs) were produced in addition to the ether-type oxygen-adducts (eth-SWCNTs). The Treated (6, 5) ep-SWCNTs show a red-shifted luminescence at ~1280 nm, which corresponds to the most transparent regions for bio-materials. Immunoassay, fluorescence vascular angiography and observation of the intestinal contractile activity of mice were demonstrated by using the produced o-SWCNTs as infrared fluorescent labels and imaging agents.