Graphene sensors: introduction and market status - Page 3

Researchers from the Vietnam Academy of Science and Technology, VNU University of Science, Hanoi University of Science and Technology and the Russian Academy of Sciences have developed a biosensor that uses graphene electrodes modified by zinc oxide nanoparticles to measure Hypoxanthine (HXA), a material that can be used as a marker for the freshness of meat. The team demonstrated the sensor’s efficacy on pork meat.

The freshness of animal meat in the food industry is an essential property determining its quality and safety. With advanced technology capable of preserving food for extended periods of time, meat can be shipped around the globe and so there is a vital need for effective testing of its condition. Despite the technological advances keeping meat fresh for as long as possible, certain aging processes are unavoidable. Adenosine triphosphate (ATP) is a molecule produced by breathing and responsible for providing energy to cells. When an animal stops breathing, ATP synthesis also stops, and the existing molecules decompose into acid, diminishing first flavor and then safety. Hypoxanthine (HXA) and xanthine are intermediate steps in this transition. Assessing their prevalence in meat indicates its freshness.

Researchers at the University of Cambridge and the University of Warwick have developed a fully 3D-printed quantum dot/graphene-based aerogel sensor for highly sensitive and real-time recognition of formaldehyde at room temperature. Formaldehyde is a known human carcinogen that is a common indoor air pollutant. However, its real-time and selective recognition from interfering gases has thus far remained challenging, especially for low-power sensors suffering from noise and baseline drift. 

The new sensor uses artificial intelligence techniques to detect formaldehyde in real time at concentrations as low as eight parts per billion, far beyond the sensitivity of most indoor air quality sensors.

Scientists at the University of California San Diego have developed an ultra-sensitive graphene-based sensor that can detect extraordinarily low concentrations of lead ions in water. The device achieved a record limit of detection of lead down to the femtomolar range, which is said to be a million times more sensitive than previous sensing technologies.

The device in this study consisted of a single layer of graphene mounted on a silicon wafer. The researchers enhanced the sensing capabilities of the graphene layer by attaching a linker molecule to its surface. This linker serves as the anchor for an ion receptor and, ultimately, the lead ions.

University of Massachusetts Amherst researchers have received an award to develop a graphene-based sweat monitor tattoos that can be applied to the skin just like a temporary tattoo and assess the molecules present, such as cortisol. The tattoos will aim to give users better insight into their health and serve as a tool for researchers to discover new early indications of diseases.

“There are a lot of vital biomolecules that are present in sweat that we need to measure to really understand overall human performance and correlation to different diseases,” says research lead and assistant professor of biomedical engineering, Dmitry Kireev.

Researchers at Peking University, University of Science and Technology Beijing and Peking University Third Hospital have reported magnetically self-assembling graphene sensors. 

While wearable sensors can provide continuous, personalized health tracking beyond clinical visits, most devices today still have fixed designs targeting single applications, lacking versatility to address users' changing needs. The team's recent work could address this issue and enable modular, reconfigurable wearable electronics customized to individuals. 

University of California San Diego researchers have developed a neural implant capable of reading brain activity that could advance research into creating a brain-computer interface (BCI) without being overly invasive.

The new implant consists of a thin transparent strip made of a polymer with several graphene electrodes 20 micrometers in diameter, each of which is connected to a circuit board via tiny wires. The strip sits on the surface of the brain allowing it to detect neural activity consisting of electrical activity and calcium activity. Unlike previous methods, the chip allows scientists to conduct longer experiments without the need to have a subject fixed in place under a microscope.

Universidad Politécnica de Madrid researchers have reported the development of an electrically tunable graphene-based biosensor that leverages sound waves to provide unprecedented infrared sensitivity and specificity at the single layer limit. By precisely matching the tunable graphene plasmon frequency to target molecular vibrations, even faint spectral fingerprints emerge clearly.

This acoustically activated approach enables precise in situ study of angstrom-scale films, unlocking new infrared applications across chemistry, biology and medicine.

Researchers at the University of Hong Kong, National Center for Nanoscience and Technology in Beijing, Harvard University and the University of Stuttgart have advanced the field of molecular sensing by developing a novel method to improve the sensitivity of surface-enhanced infrared absorption (SEIRA). SEIRA uses plasmonic nanostructures to amplify the infrared signals of molecules adsorbed on their surface. Graphene is a particularly promising material for SEIRA because of its high sensitivity and tunability. However, the interaction between graphene and molecules is weakened by intrinsic molecular damping.

The new approach employs synthesized complex-frequency waves (CFW) to amplify the molecular signals detected by graphene-based sensors by at least an order of magnitude. It also applies to molecular sensing in different phases.

HydroGraph Clean Power has announced that its flagship graphene product, FGA-1, has been successfully trialed in Hawkeye Bio’s biomedical sensor aimed at the early detection of lung cancer. Hawkeye Bio is a clinical stage medical technology company focused on the early detection of cancer.

HydroGraph’s graphene was selected by Hawkeye Bio based on the purity and consistency of its graphene. Headquartered in Toronto, HydroGraph’s manufacturing facility is located in Manhattan, Kan.

Researchers from Zhejiang University, Zhiyuan Research Institute and Nanjing University of Posts and Telecommunications have reported a thin elastic conductive nanocomposite that is formed by cryogenically transferring laser-induced graphene (LIG) to a hydrogel film. 

The low-temperature atmosphere enhances the interfacial bonding between the defective porous graphene and the crystallized water within the hydrogel. Using the hydrogel as an energy dissipation interface and out-of-plane electrical path, continuously deflected cracks can be induced in the LIG leading to an over fivefold enhancement in intrinsic stretchability.