Researchers at the College of Science and Engineering of the University of Minnesota have developed a new exclusive device that uses graphene from the wonders material that provides the first step toward ultrasensitive biosensors to detect diseases at the molecular level with a & Almost perfect efficiency.
Ultrasensitive biosensors for probing protein structures could greatly improve the depth of diagnosis for a wide variety of diseases that extend to 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 the development of new pharmaceutical compounds.
The research was published in Nature Nanotechnology a peer-reviewed scientific journal published by Nature Publishing Group.
"To detect and cure many diseases we need to detect protein molecules in small quantities and understand their structure," said Sang-Hyun Oh, professor of electrical and computer engineering at the University of Minnesota and chief researcher of the study. "Currently there are many technical challenges with this process, we hope that our device that uses graphene and a single production process will provide the fundamental research that can help you overcome those challenges."
Graphene, a material made up of a single layer of carbon atoms, was discovered more than a decade ago. He has fascinated researchers with its range of incredible properties that have been used in many new applications, including creating better sensors for detecting diseases.
Significant attempts have been made to improve the biosensors using graphene, but the challenge exists with its extraordinary single-atom thickness. This means that it does not interact efficiently with light when it is projected through it. The absorption of light and conversion into local electric fields are essential for the detection of small amounts of molecules during the diagnosis of diseases. Previous research using similar graphene nanostructures has shown a light absorption rate of less than 1
In this new study, researchers from the University of Minnesota combined graphene with nanoscale gold metal strips. Using adhesive tape and a high-tech nanofabrication technique developed at the University of Minnesota, called "template stripping", the researchers were able to create a surface of the ultra-flat base layer for graphene.
So they used the energy of light to generate an electron sloshing movement in graphene, called plasmons, which can be thought of as ripples or waves that spread through a "sea" of electrons. Likewise, these waves can increase the "giant tidal waves" of local electric fields based on the intelligent design of the researchers.
By illuminating the light on the graphene layer device with a single atom, they were able to create a plasmon wave with unprecedented efficiency with a nearly perfect 94% light absorption in "tides" of field electric. When they inserted the protein molecules between graphene and metal strips, they were able to use enough energy to visualize individual layers of protein molecules.
"Our computer simulations showed that this new approach would work, but we were still a little surprised when we achieved 94% light absorption in real devices," said Oh, who holds the Sanford P. Bordeau Chair in Electrical Engineering at the University of Minnesota. "Making an ideal from a computer simulation has so many challenges: everything must be so high quality and atomically flat, the fact that we could get such a good agreement between theory and experiment was quite surprising and exciting."
Waterproof graphene electronic circuits
In-Ho Lee et al., Graphene acoustic plasmon resonator for ultrasensitive infrared spectroscopy, Nature Nanotechnology (2019). DOI: 10.1038 / s41565-019-0363-8