Biology - Page 2

Researchesr from Korea's Ulsan, KAIST and ETRI institutes developed a process that produces flexible transparent graphene electrodes that can be attached to the skin (or any kind of delicate object). This could enable applications such as electronic tattoo-like stickers or bio-signal sensors.

A graphene metal fiber composite ise used, which lowers the resistance of the transparent electrode to approximately 1/20th of existing ones. This enables the electrodes to be used in flexible displays or sensors. The new process is similar to a widely-used semiconductor process which means that this can be scaled commercially.

Researchers from from Zhejiang Normal University in China developed a biocompatible bio-sensor that can simultaneous detection multiple biomarkers, such as DNA and proteins. Those sensors are made from carbon materials - mainly graphene-oxide (GO) and graphene quantum dots (GQDs).

The researchers explain hat GQDs rae promising environmentally friendly and biocompatible nanomaterials that can be used to design new fluorescence detection platforms in vitro and in vivo. The researchers use the specifically designed fluorescence on-off-on process that takes advantage of the intense and dual-color fluorescence of the GQDs, in addition to the efficient quenching effect of GO. The high emission efficiency of GQDs guarantees the high sensitivity of the constructed biosensors, while the good biocompatibility is promising for use of biosensors in vivo.

Researchers from India developed a new superparamagnetic hybrid material made from graphene and the amaranthus dubius plant. This plant is used for food (it's high on protein and contains several vitamins and minerals). Superparamagnetic materials can be used to make very sensitive and accurate sensors.

This new material is biologically inert (as both graphene and the plant are inert) and so this may be useful for applications in biology (such as bio-sensors).

Researchers at Melbourne's Swinburne University developed a high-quality continuous graphene oxide thin film that has a record-breaking optical nonlinearity. The film may be suitable for high performance integrated photonic devices - useful for communication, biomedcine and photonic computing.

To create this new film, the researchers first spin-coated a graphene-oxide solution on a glass substrate. They then used a laser to create microstructures on the graphene oxide film to tune the nonlinearity of the material. Now they have a platform to fabricate optical components with desired nonlinearity - and all on the same graphene sheet without the need to integrate different components.

Researchers from the University of Pennsylvania developed an artificial chemical sensor based on one of the human body’s most important receptors (mu-opioid), one that is critical in the action of painkillers and anesthetics.

The researchers attached a modified version of this mu-opioid receptor to strips of graphene, and have paved a way towards mass production of such sensors, which could be useful for drug development and diagnostics.

Korean researchers developed a liquid-ion gated FET-type graphene-based aptasensor with highly sensitive and selective responses to various mercury ion concentrations. This sensor was shown to be a good detector of mercury in mussels.

Aptasensors are bio-sensors that use aptamers (artificial oligonucleotides: DNA or RNA) as a recognition element. The sensors developed in korea used a single-layer graphene sheet that was functionalized using an aptamer. This sensor is not just very sensitive and fast, but it's also flexible and highly stable mechanically.

Researchers from from Sweden's Linköping University managed to fabricate an on/off switchable zipper-like graphene interface in order to control interaction between biomolecules and electrode materials. Using electrochemical techniques, the researchers hope that this can lead the way towards development of an auto-switchable graphene bio-interface based bio-devices.

The researchers developed a "zipper" that is made from a graphene donor and a polymeric receptor, which are assembled together based in a stoichiometric interaction. At about 20 degrees Celsius, hydrogen bonding creates a coalescence of the graphene interface, thereby causing considerable shrinkage in the donor-to-acceptor interface. Thus access of an associated enzyme to its substrate is largely restricted, resulting in a decrease in the diffusion of reactants and the consequent activity of the system.

Researchers from the University of Manchester demonstrated how membranes can be "written" on to a graphene sheet surface using a technique known as Lipid Dip-Pen Nanolithography (L-DPN). The researchers have shown that graphene is a great surface for human-cell membrane research. Graphene combined with lipids may also enable new types of bio-sensors.

The researchers wanted to find a new way to study human cell phospholipid bi-layer membranes, which protect the cells.The membranes contain proteins, ion channels and other molecules, each performing vital functions. Researchers already developed model cell membranes on surfaces outside the body for research purposes. The new research have shown that graphene is a great surface to assemble said membranes and research them.

Researchers from the University of Michigan developed a new microfluidic chip based on Graphene Oxide that can capture tumor cells from blood and support their growth for further analysis. This device could be used for both cancer diagnosis and find the best test-treatment options, without biopsies. The researchers estimate that such chips could reach clinics within 3 years.

Circulating tumor cells may be crucial for new early cancer diagnosis technologies. The researchers call this "liquid biopsy". This diagnosis may also help researchers understand the basic biologic mechanisms by which cancer cells metastasize or spread to distant organs, which is the major cause of death in cancer patients.

Researchers from Seoul National University developed a simple method to produce graphene nanonet (GNN) patterns on large areas. The patterns, which contain continuous networks of chemically functionalized graphene nanoribbons, could be used to make biosensor devices. These patterns behave better than GO or GNRs which are commonly used for biological sensing applications and are easy to make.

The GNN structures are made from continuous networks of GNRs with chemical functional groups on their edges. The chemical functional groups in the GNN can be functionalized with biological molecules such as DNA for biochip applications. The researchers successfully performed fluorescence imaging of DNA molecules on the GNN channels and has electrically detected the DNA at 1 nM concentrations using the GNN-based biochip devices.