The concept of e-noses - electronic devices which mimic the olfactory systems of mammals and insects - is well developed and has become a booming area of research thanks to a better understanding of the reception, signal transduction and odor recognition mechanisms for mammals, combined with achievements in material science, microelectronics and computer science. Researchers have now started replacing the sensing elements in e-noses with nanowires, achieving excellent sensing performance which is comparable or even better compared to the best thin film counterparts.
Researchers at the University of Sydney have revealed a new structural evolution of carbon nanotubes (CNTs) in epoxy composites during contact sliding and have shown that the evolution has three stages which are a) the bonding breakage of the CNTs, b) the formation of sinusoidal shells, and c) the consolidation of nanoparticles. This may present a potentially effective way to obtain nanoparticles with controlled structure and size.
The oxidation-assisted temperature measurement with carbon nanotube nanothermometers that contain liquid gallium is a novel and reliable method that can be used over a moderate temperature range and can be applied in any environment where air is present. All the other available techniques that are capable to measure temperature at the nanometer scale are limited by either that they are only workable in a very narrow temperature range or that they can only be applied in a special environment.
Nanoscale sensors based on silicon nanowires and carbon nanotubes are capable of detecting molecules at ultra low concentrations. The potential applications include early detection of cancer and fast sequencing of genome. However, for these applications, the time taken by the sensor to reach stable response is crucial. This time is dictated by the diffusion of molecules (e.g. cancer markers) through the solution and their subsequent capture at the sensor surface. Researchers at Purdue University show that this response is governed by the geometry of diffusion of the system and that nanobiosensors are capable of detecting bio-molecules at much lower concentration than the classical planar sensors.
Researchers in South Korea used single-walled carbon nanotubes (SWNTs) to tag single-stranded DNA to locate a particular sequence of DNA within a complex genome. The results show that SWNTs may be used as generic nano-biomarkers for the precise detection of specific kinds of genes.
Addressing the potential hazards associated with nanomaterials requires a comprehensive approach to gaining, collecting and publishing knowledge about individual nanomaterials. Expanding MSDS (Material Safety Data Sheets) into nMSDS for nanomaterials could be a way to accomplish this.
A new method based on the nanoscale Kirkendall effect was demonstrated to fabricate compound nanotubes. Through a spinel-forming solid-state reaction, high aspect-ratio core-shell ZnO-Al2O3 nanowires transform into monocrystalline ZnAl2O4 nanotubes.
Researchers at the University of Illinois at Urbana-Champaign have shown that, by employing small pieces of DNA molecules called aptamers, nanomaterials can be smart enough to assemble or disassemble only in the presence of programmable signals such as AND or OR, with controllable cooperativity.