Photo courtesy of Victor Anaskin.
Story highlights
- Russian researchers develop graphene oxide biosensor
- Graphene oxide biosensors are attractive due to their large surface area, low-cost fabrication, and interaction with a wide range of biomolecules.
- Graphene oxide has more attractive optical and chemical properties than pristine graphene.
- The GO based sensor chips are attractive commercially due to their simplicity and low-cost fabrication compared to sensor chips that are already commercially available.
(2D Materials Magazine)- Researchers from the Laboratory of Nanooptics and Plasmonics, Moscow Institute of Physics and Technology have developed a graphene oxide (GO)-based biosensor for application in drug development. The device could enable the faster development of new drugs and vaccines against diseases such as HIV, hepatitis and cancer.
Surface plasmon resonance (SPR)
According to the the researchers, the graphene oxide biosensor chips exploit the phenomenon of surface plasmon resonance (SPR). Surface plasmons are electromagnetic waves propagating along a metal-dielectric interface (e.g., gold/air) and having the amplitudes exponentially decaying in the neighbor media. Adsorption of molecules from solution onto a sensing surface alters the refractive index of the medium near this surface and, therefore, changes the conditions of SPR. These sensors can detect biomolecule adsorption even at a few trillionth of a gram per millimeter square.
According to researcher Yury Stebunov
“SPR biosensing is a valuable tool to investigate a wide range of biochemical reactions, estimate their chemical kinetics and other characteristics. All this can be efficiently used for new drug discovery and validation. Widespread introduction of this method into preclinical trials will completely change the pharmaceutical industry. With SPR sensors we just need to estimate the interaction between the drug and targets on the sensing surface,”
The researchers commented that most commercial SPR sensor chips comprise a thin glass plate covered by gold layer with thiol or polymer layers on it. The biosensing sensitivity depends on the properties of chip surface. Higher binding capacity for biomolecules increases the signal levels and accuracy of analysis. They have created and patented novel SPR sensor chips with the linking layer comprised of GO.
Graphene oxide biosensor
The GO “flakes” were deposited on the 35 nm gold layer. Thereafter a layer of streptavidin protein was developed on GO for selective immobilization of biomolecules. The researchers conducted a series of experiments with the GO chip, the commercially available chip with carboxymethylated dextran (CMD) layer and the chip covered by monolayer graphene. Experiments showed that the proposed GO chip has three times higher sensitivity than the CMD chip and 3.7 times than the chip with pristine graphene. These results mean, that the new chip needs much less molecules for detecting a compound and can be used for analysis of chemical reactions with small drug molecules.
“Our invention will help in drug development against viral and cancer diseases. We are expecting that pharmaceutical industry will express a strong demand for our technology,” Stebunov says. “The sensor can also find applications in food quality control, toxin screening, the sensor can significantly shorten a time for a clinical diagnostic.”
Further information:
“Highly sensitive and selective sensor chips with graphene-oxide linking layer.”
