Microbiology relates to nanoscience at a number of levels. Many bacterial entities are nano-machines in nature, including molecular motors like flagella and pili. Bacteria also form biofilms by the process of self-assembly. The formation of aerial hyphae by bacteria and fungi is also directed by the controlled and ordered assembly of building blocks. Also, the formation of virus capsids is a classical process of molecular recognition and self-assembly at the nanoscale. Nanoscience does have an impact on several areas of microbiology. It allows for the study and visualization at the molecular-assembly levels of a process. It facilitates identification of molecular recognition and self-assembly motifs as well as the assessment of these processes.
Early detection of food borne pathogenic bacteria is critical to prevent disease outbreaks and preserve public health. This has led to urgent demands to develop highly efficient strategies for isolating and detecting this microorganism in connection to food safety, medical diagnostics, water quality, and counter-terrorism. Conventional techniques to detect E. coli and other pathogenic bacteria are time-consuming, labor-intensive, and inadequate as they lack the ability to detect bacteria in real time. Thus, there is an urgent need for alternative platforms for the rapid, sensitive, reliable and simple isolation and detection pathogens. Taking a novel approach to isolating pathogenic bacteria from complex clinical, environmental and food samples, researchers have developed a nanomotor strategy that involves the movement of lectin-functionalized microengines. Receptor-functionalized nanoswimmers offer direct and rapid target isolation from raw biological samples without preparatory and washing steps.
Researchers have, for the first time, compared the energetic cost of silk and synthetic polymer fiber formation and demonstrated that, if we can learn how to spin like the spider, we should be able to cut the energy costs for polymer fiber processing by 90%, leaving alone the heat treatment requirements. The two routes of polymer fiber-spinning - one developed by nature and the other developed by man - show striking similarities: both start with liquid feed-stocks sharing comparable flow properties; in both cases the 'melts' are extruded through convergent dye designs; and for both 'spinning' results in highly ordered semicrystalline fibrous structures. In other words, analogous to the industrial melt spinning of a synthetic polymer, in the natural spinning of a silk the molecules (proteins) align (refold), nucleate (denature) and crystallize (aggregate).
Ultra- or supercapacitors are emerging as a key enabling storage technology for use in fuel-efficient transport as well as in renewable energy. These devices combine the advantages of conventional capacitors - they can rapidly deliver high current densities on demand - and batteries - they can store a large amount of electrical energy. Supercapacitors offer a low-cost alternative source of energy to replace rechargeable batteries. Although the energy density of capacitors is quite low compared to batteries, their power density is much higher, allowing them to provide bursts of electric energy. Researchers have now fabricated novel high-performance sponge supercapacitors using a simple and scalable method. Their results shows that three-dimensional electrodes potentially have a huge advantage over conventional mixed electrode materials.
Directed self-assembly of block copolymers is a candidate lithography for use in future nanoelectronics and patterned media copolymer with resolutions down to the sub-10nm domain. Variations of this effective nanofabrication technique have been used to write periodic arrays of nanoscale features into substrates at exceptionally high densities with resolutions that are difficult or impossible to achieve with top-down techniques alone. However, in many cases these approaches are either too costly or too complex due to the required number of processing steps, for instance expensive, time-consuming substrate pre-patterning. Researchers at the Molecular Foundry have now shown that block copolymers can be aligned on an unpatterned substrate using a removable and reusable mold applied from above.
Many batteries still contain heavy metals such as mercury, lead, cadmium, and nickel, which can contaminate the environment and pose a potential threat to human health when batteries are improperly disposed of. Not only do the billions upon billions of batteries in landfills pose an environmental problem, they also are a complete waste of a potential and cheap raw material. Unfortunately, current recycling methods for many battery types, especially the small consumer type ones, don't make sense from an economical point of view since the recycling costs exceed the recoverable metals value. Researchers in India have carried out research to address the recycling of consumer-type batteries. They report the recovery of pure zinc oxide nanoparticles from spent Zn-Mn dry alkaline batteries.
Surface-enhanced Raman spectroscopy (SERS) is a powerful research tool that is being used to detect and analyze chemicals as well as a non-invasive tool for imaging cells and detecting cancer. It also has been employed for label-free sensing of bacteria, exploiting its tremendous enhancement in the Raman signal. SERS can provide the vibrational spectrum of the molecules on the cell wall of a single bacterium in a few seconds. Such a spectrum is like the fingerprints of the molecules and therefore could be exploited as a means to quickly identify bacteria without the need of a time-consuming bacteria culture process, which typically takes a few days to several weeks depending on the species of bacteria. To practically apply SERS to the early diagnosis of bacteremia - the presence of bacteria in the blood - researchers have managed to capture bacteria in a patient's blood onto the SERS substrate.
Graphene research papers are popping up left and right at what seems like an accelerating speed and growing volume. One of the areas that is seeing vast research interest is the biological interfacing of graphene for instance for sensor applications. Today, we are looking at another exciting graphene bio application where a graphene sensor is integrated with microfluidics to sense malaria-infected red blood cells at the single-cell level. Specific binding between ligands on positively charged knobs of infected red blood cells and receptors functionalized on graphene inside microfluidic channels induces a distinct conductance change. Conductance returns to baseline value when infected cell exits the graphene channel.