Graphene sensors: introduction and market status - Page 47

Scientists at the Indian Institute of Engineering Science and Technology (IIEST) discovered that reduced graphene oxide (rGO) can be used in a unique sensor to detect a deadly cancer-causing food toxin with high sensitivity.

The toxin, Aflatoxin B1, is a common contaminant in peanuts, chillies, cottonseed meal, corn, rice and other grains. Produced by a fungus, it is a potent liver carcinogen that damages the immune system in humans and animals.

Scientists at the University of Illinois at Chicago engineered a humidity sensor on a bacterial spore. They call it NERD, for Nano-Electro-Robotic Device. They've taken a spore from a bacteria and put graphene quantum dots on its surface, then attached two electrodes on either side of the spore. Then they change the humidity around the spore,causing the spore to shrink. As it shrinks, the quantum dots come closer together, increasing their conductivity, as measured by the electrodes.

The researchers report a very sharp reaction once the humidity is changed, around 10 times faster than a sensor made with the most advanced man-made water-absorbing polymers. There was also better sensitivity in extreme low-pressure, low-humidity situations. The researchers also said it is possible to go all the way down to a vacuum and see a response, which is important in applications where humidity must be kept low,like preventing corrosion or food spoilage and space applications, where any change in humidity could signal a leak.

Back in 2013, Rice scientists developed a simple method to reduce coal into graphene quantum dots (GQDs). Now, these Rice researchers have found a way to engineer these GQDs for specific semiconducting properties in two separate processes.

The researchers' work demonstrates precise control over the graphene oxide dots' band gap, the very property that makes them semiconductors. By sorting the QDs through ultrafiltration, it was found possible to produce quantum dots with specific semiconducting properties. The second process involved direct control of the reaction temperature in the oxidation process that reduced coal to quantum dots. The researchers found hotter temperatures produced smaller dots that had different semiconducting properties. The dots in these experiments came from treatment of anthracite, a kind of coal. The processes produce batches in specific sizes between 4.5 and 70 nanometers in diameter.

Scientists from Ulsan National Institute of Science and Technology (UNIST) and Pohang University of Science and Technology in South Korea synthesised nitrogenated 2D crystals using a simple chemical reaction in liquid phase.

Introducing foreign elements (there are not carbon) into graphene's carbon lattice structure is a known way of developing other 2D crystals. Nitrogen has a suitable atomic size and structure to fit into a strong network of carbon atoms, by creating bonds in which electrons are shared by the whole network.

Researchers at the Indian Institute of Science (IIS) designed a device based on graphene and metal nanoparticles that shows a significant response to light and is colour sensitive. This may be greatly beneficial for applications like ultra-sensitive photodetectors and efficient solar cells.

The scientists display a device with a large number of stacked silver nanoparticle pairs, all separated precisely by just one-third of a nanometer using graphene. All light interaction related properties are found to be enhanced in this unique device structure. The graphene acts as a perfect spacer and this produces an unprecedented field enhancement of nearly a million times in between the nanoparticles, boosting the interaction with light. As a result, the Raman signal in this device was found to be 100 times more intense. This is of significance because although graphene responds to a large range of light frequencies (colours) and has a very fast response, it does not absorb light very well by itself.

A science and technology roadmap for graphene, related two-dimensional crystals, other 2d materials, and hybrid systems was put together in a joint effort by over 60 academics and industrialists. The roadmap covers the next 10 years and beyond, and its objective is to guide the research community and industry toward the development of products based on graphene and related materials.

The roadmap highlights three broad areas of activity. The first task is to identify new layered materials, assess their potential, and develop reliable, reproducible and safe means of producing them on an industrial scale. Identification of new device concepts enabled by 2d materials is also required, along with the development of component technologies. The ultimate goal is to integrate components and structures based on 2d materials into systems capable of providing new functionalities and application areas.

The Canadian Graphene Sensors Inc. announced the signing of a memorandum of understanding with Meditel, a major hospital chain based in Chennai, India. According to the agreement, Meditel will test and evaluate the Company’s GS7 Sensor and provide the Graphene Sensors Inc. with detailed feedback as appropriate.

Graphene Sensors Inc. relayed that the relationship with Meditel is a great opportunity as it is a leading medical tech developer in India, and to work with their team of surgeons will help the company to continue to advance the development of robotic surgical technologies. Meditel's chairman added that "Nano assisted surgery represents one of the most exciting innovations in thoracic, abdominal and pelvic surgery in years. We look forward to offering these procedures to our patients to help combat cardiac disease, as well as prostate and uterine cancer.

Haydale announced it has entered into a 5 year exclusive pipeline agreement with Swansea University and Swansea Innovations.

The agreement stipulates that Swansea will carry out a series of internally funded research projects to produce prototype applications using a range of Haydale materials. These materials can be the functionalised Haydale Graphene Nano Platelets (GNPs), and the Haydale conductive and insulating inks formulated by its collaboration partner the Welsh Centre for Printing and Coating (WCPC).

Researchers at the Indian Banaras Hindu University (BHU) designed a sensitive and specific graphene oxide-based electrochemical biosensor for detection of specific micro-particles in blood samples and predict the risk of heart attack or brain stroke.

The scientists explain that certain processes that take place in the body prior to brain stroke or cardiac arrest cause the release of microparticles to the blood, which can be detected by the sensor to predict an imminent stroke or heart attack.

The UK's Whitworth Art Gallery reopened its doors, in a ceremony marked by a unique firework display.

Graphene Noble laureate Kostya Novoselov teamed up with an artist called Cornelia Parker to put together what was defined as the first cultural use of graphene: after collecting tiny graphene particles from some of the Whitworth’s most prized works, the artists created what they called a meteor shower, that to the rest of the viewers looked like a firework display.