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A review is presented of one-dimensional cutting lines that are utilized to obtain the physical properties of carbon nanotubes from the corresponding properties of graphite by the zone-folding scheme. Quantization effects in general low-dimensional systems are briefly discussed, followed by a more detailed consideration of one-dimensional single-wall carbon nanotubes. The geometrical structure of the nanotube is described, from which quantum confined states are constructed. These allowed states in the momentum space of graphite are known as cutting lines. Different representations of the cutting lines in momentum space are introduced. Electronic and phonon dispersion relations for nanotubes are derived by using cutting lines and the zone-folding scheme. The relation between cutting lines and singularities in the electronic density of states is considered. The selection rules for carbon nanotubes are shown to be directly connected with the cutting lines. Different experimental techniques are considered that confirm the validity of cutting lines and the zone-folding approach.

A novel non-enzymatic glucose sensor based on poly(caffeic acid)@multi-walled carbon nanotubes decorated with CuO nanoparticles (PCA@MWCNT-CuO) was developed. The described approach involves the complexation/accumulation of Cu(II) on PCA@MWCNT followed by electrochemical CuO deposition in an alkaline electrolyte. The morphology and surface characteristics of the nanomaterial were determined by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), Raman spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS). A hybrid-support sensor device was then developed to assess the glucose concentration in different solutions. The sensitivity of the electrode is 2412 μA mM -1  cm -2 . The electrode exhibited a broad linear range of 2 µM to 9 mM and a low limit of detection (LOD) of 0.43 µM (relative standard deviation, RSD = 2.3%) at + 0.45 V vs Ag/AgCl. The excellent properties obtained for glucose detection were most likely due to the synergistic effect of the combination of individual components: poly(caffeic acid), MWCNTs, and CuO. Good accuracy and high precision were demonstrated for quantifying glucose concentrations in human serum and blood samples (the recovery ranged from 95.0 to 99.5%). The GC/PCA@MWCNT-CuO sensor represents a novel, simple, and low-cost approach to the fabrication of devices for amperometric sensing of glucose., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

The increasing engineering of carbon-based nanomaterials as components of neuroregenerative interfaces is motivated by their dimensional compatibility with subcellular compartments of excitable cells, such as axons and synapses. In neuroscience applications, carbon nanotubes (CNTs) have been used to improve electronic device performance by exploiting their physical properties. Besides, when manufactured to interface neuronal networks formation in vitro, CNT carpets have shown their unique ability to potentiate synaptic networks formation and function. Due to the low optical transparency of CNTs films, further developments of these materials in neural prosthesis fabrication or in implementing interfacing devices to be paired with in vivo imaging or in vitro optogenetic approaches are currently limited. In the present work, we exploit a new method to fabricate CNTs by growing them on a fused silica surface, which results in a transparent CNT-based substrate (tCNTs). We show that tCNTs favor dissociated primary neurons network formation and function, an effect comparable to the one observed for their dark counterparts. We further adopt tCNTs to support the growth of intact or lesioned entorhinal-hippocampal complex organotypic cultures (EHCs). Through immunocytochemistry and electrophysiological field potential recordings, we show here that tCNTs platforms are suitable substrates for the growth of EHCs and we unmask their ability to significantly increase the signal synchronization and fiber sprouting between the cortex and the hippocampus with respect to Controls. tCNTs transparency and ability to enhance recovery of lesioned brain cultures, make them optimal candidates to implement implantable devices in regenerative medicine and tissue engineering., (© 2019 Wiley Periodicals, Inc.)