Graphene sensors: introduction and market status - Page 51

Researchers from Monash University discovered that graphene oxide flakes can spontaneously change their structure - to become liquid crystal droplets, in the presence of an external magnetic field. This could be very useful for applications such as drug delivery and disease detection.

It's common for current drug delivery systems to use magnetic particles - useful for drug release. But most magnetic particles are toxic in some conditions. Now the researchers hope that the new graphene discovery means it can be a better system than what's available today.

The National Science Foundation of China (NSFC) awarded an 18-month Young International Researcher Fellowship to a University of Cambridge researcher that will look to se graphene materials composites for organic optoelectronic compounds. The researcher hope to use inkjet printers to produce those devices and then integrate them into displays, light detectors and gas sensors.

In plain English, it means that they hope these kind of devices will enable flexible, cheap and fast cameras. Compared to current printed organic circuits, the graphene-based will be less sensitive to temperature and moisture and will also offer much faster response time that is suited for photodetection.

Researchers from the University of Michigan developed a graphene-enabled wearable vapor sensor - that can be used for continuous disease monitoring, for diabetes, high blood pressure, anemia or lung disease. The sensor can detect airborne chemicals either exhaled or released through the skin.

The researchers can sense several biomarkers that indicate the presence of diseases. For example, acetone is a marker of diabetes. It can also detect nitric oxide and oxygen which abnormal levels may indicate high blood pressure, anemia or lung disease.

Two weeks ago, Graphene Frontier announced that they raised $1.6 million, which will be used to expand operations and accelerate the development of their proprietary GFET sensors and manufacturing process. Graphene Frontiers launched the "six sensors" brand for highly-sensitive chemical and biological GFET-based sensors that can be used to diagnose diseases with multiple markers such as cancers and illnesses currently diagnosed using ELISA technologies.

I asked the company to explain a little more on this interesting new sensor platform. It turns out that the sensor is based on a functionalized graphene field effect transistor (GFET). The unique properties of graphene enable detection of molecules in femtomolar (fM) concentrations - this is vastly better than any other sensor on the market.

Researchers from the University of Manchester developed a new way to modify the transmission of light that goes through a silicon wire (waveguide) - by wrapping graphene around the wire. Such silicon waveguide can be used to build a photonic microchip, and have also applications in highly sensitive bio-chemical sensor devices and perhaps photo detectors too.

The waveguides in this research are built in loops shaped like oval racetracks - and are called racetrack resonators. In a bio-chemical sensor, the light that leaks out of the waveguide is used for chemical sensing. The graphene coating adds further capabilities to such a sensor, such as making it more sensitive and selective. The researchers say that the graphene dramatically alters the way the light is guided through the device.

Graphene Frontier, spun off from the University of Pennsylvania, is producing graphene using their own Atmospheric Pressure CVD (APCVD) technology, a roll-to-roll process that does not require a vacuum. We now hear that the company raised $1.6 million in Series Seed B funding.

The round was led by Trimaran Capital Partners with participation from R2M Investments and return backers WEMBA 36 Angels. Graphene Frontiers will use the money to hire additional researchers, expand the lab facilities and accelerate the development of their proprietary GFET sensors and manufacturing process.

Researchers from Nankai University developed a single-cell sensor (optical refractive index sensor) based on graphene field-effect transistors. This new sensor is able to detect a single cancer cell.

The researchers managed to obtain such ultrahigh sensitivity by controlling the thickness of high-temperature reduced graphene oxide. The resolution obtained is the highest values reported for refractive index sensors."

It has been shown before (here, and here for example) that graphene can make excellent highly sensitive strain sensors. One of the applications is human health evaluation via physiological motion detection and now researchers from two universities in China developed a method that uses graphene based sensors to monitor human motions.

The researchers developed simple-structured and low-cost graphene woven fabrics (GWFs) strain sensor. The GWFs were made using CVD to grow graphene on crisscross copper meshes. The copper mash was later etched away and the graphene fabric was transferred to a pretreated film composited with medical tape and PDMS glue, which is a flexible, biocompatible, shape controllable material. Silver wires were used to connect the graphene.

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.

Researchers from the University of Nebraska-Lincoln developed a chemical process to produce graphene nanoribbons (GNRs). This bottom-up method can be used to produce very narrow GNRs (2 nanometers wide). The researchers say it is easy to scale up their process.

The team is now testing their ribbons for applications in electronics, gas sensors and solar cells. The electronic properties of their GNRs can be tuned by changing the synthetic conditions.