Graphene sensors: introduction and market status - Page 23

Researchers from Myongji University, Sungkyunkwan University, Gachon University and Korea Institute of Science and Technology in South Korea, along with U.S-based Villanova University, have developed a new device concept for bacterial sensing by Raman spectroscopy and voltage-gated monolayer graphene.

Synthesis of the monolayer graphene was done by chemical vapor deposition (CVD) on a Cu foil, which was eventually channelized onto a SiO₂ /Si substrate. Modification of Raman spectra is examined in the study in order to develop ultra-sensitive biosensing techniques for the detection, identification, differentiation and classification of bacteria associated with infectious diseases.

A research group at the University of Tartu in Estonia has been working on a graphene-enhanced sensor nose for five years and presented their latest prototype in February at the Barcelona World Mobile Congress in the Graphene Pavilion.

The prototype does not look anything like a mobile phone yet; it is quite big and would not fit in a pocket. But it already has a processor, Bluetooth, GPS and touchscreen. ‘We met many people there who really needed it and were a little disappointed that we didn’t have the product ready yet,’ says Raivo Jaaniso, head of the laboratory and a senior research fellow at the University of Tartu. But big breakthroughs always require time and the project is halfway complete, with plenty of work and experimenting ahead for the next four years.

Archer Exploration has printed and patterned ink formulations of human antibodies on graphene-based biosensor components derived from the company’s Campoona graphite. Archer reports that ink formulations comprised primarily of human antibody immunoglobulin G (IgG) as the active constituent were successfully prepared and printed using proprietary methods.

An antibody ink formulation printed and patterned onto a resin-coated paper substrate

The IgG inks were printed on resin-coated paper and a number of graphene-based electrodes and were able to withstand the chemical and physical processes in the formulation, printing, and post-printing steps.

Scientists from ICFO have developed a novel graphene-enabled photodetector that operates at room temperature, and is sad to be highly sensitive, very fast, with a wide dynamic range and covers a broad range of THz frequencies.

Schematic representation of the central part of the graphene-based THz photodetector device

Detecting terahertz (THz) light is extremely useful for two main reasons: First, THz technology is becoming a key element in applications regarding security (such as airport scanners), wireless data communication, and quality control but current THz detectors have shown strong limitations in terms of simultaneously meeting the requirements for sensitivity, speed, spectral range, being able to operate at room temperature, etc. Second, it is a very safe type of radiation due to its low-energy photons, with more than a hundred times less energy than that of photons in the visible light range.

The EU Graphene Flagship has published its graphene application roadmap, showing when the flagship expects different graphene applications to mature and enter the market.

As can be seen in the roadmap above (click here for a larger image), the first applications that are being commercialized now are applications such as composite functional coatings, graphene batteries, low-cost printable electronics (based on graphene inks), photodetectors and biosensors.

Mitsubishi has reportedly developed graphene-based MWIR sensors with extraordinarily high sensitivity. Thanks to an internal graphene FET gain, the responsivity is said to be 10 times higher than that of quantum-type IR sensors with no internal amplification. Mitsubishi uses graphene FET and leverages its high electron mobility.

Other than a graphene-based FET, reports suggest that there is "a light-amplifying part" that produces photoelectrons and photoholes and is placed under the graphene. At a very low temperature of, for example, 80K, the responsivity increases even more, by a factor of 100x.

Cardea, (formerly called Nanomedical Diagnostics), U.S-based manufacturer of a biology-enabled transistor technology made from graphene-based biosensors, announced that it raised $7.8 million Series A-1 financing.

The round was led by Alexandria Venture Investments, with participation from new and existing investors, including Series A round lead investor Serra Ventures. Jonathan Kabakoff, senior principal, science and technology at Alexandria Venture Investments, has taken a seat on Cardea’s board of directors, joining early investor Tim Hoerr, CEO and managing partner at Serra Ventures.

Researchers at Swinburne, the University of Sydney and Australian National University have collaborated to develop a solar absorbing, ultra-thin graphene-based film with unique properties that has great potential for use in solar thermal energy harvesting.

The 90 nanometre material is said to be a 1000 times finer than a human hair and is able to rapidly heat up to 160°C under natural sunlight in an open environment.

Researchers in the University of Minnesota College of Science and Engineering have developed a unique new device using graphene that provides the first step toward ultrasensitive biosensors to detect diseases at the molecular level with excellent efficiency.

Ultrasensitive biosensors for probing protein structures could greatly improve diagnosis of a wide variety of diseases extending to both humans and animals. These include Alzheimer’s disease, Chronic Wasting Disease, and mad cow disease—disorders related to protein misfolding. Such biosensors could also lead to improved technologies for developing new pharmaceutical compounds.

Researchers at Tsinghua University designed graphene-based e-tattoos that act as biosensors. The sensors can collect data related to the user's health, such as skin reactions to medication or to assess the degree of exposure to ultraviolet light.

The use of graphene aids the collection of electric signals and also imparts material properties to the sensors, allowing them to be bent, pressed, and twisted without any loss to sensors functionality. The new sensors have reportedly shown via as series of tests good sensitivity to external stimuli like strain, humidity, and temperature. The basis of the sensor is a material matrix composed of a graphene and silk fibroin combination.