Early diagnosis of an infectious viral disease can help the patients and health care professionals monitor the outbreaks accurately and provide treatment at the early stage of a disease, avoiding any detrimental consequences. The accuracy of information is essential while monitoring such diseases to prevent any possible pandemics.
An article published in the journal ACS Applied Materials and Interfaces discussed the fabrication of highly sensitive sensors, freestanding laser-induced graphene (FLIG) flakes, for highly reliable viral detection. Here, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins were detected by using FLIG flakes.
The FLIG flakes were nonembedded porous graphene foams of 30-micrometer thickness and were generated using polyamide laser irradiation at a low cost. The larger pieces of the FLIG were cut into a cantilever and used as suspended resonators.
Additionally, a protocol was developed for aqueous biological sensing of SARS-CoV-2 spike proteins. Herein, the device was functionalized with coronavirus disease 2019 (COVID-19) antibodies, and the wetting dynamic response of graphene sensors was characterized in buffer solution and water. Moreover, the designed device could specifically detect SARS-CoV-2 spike protein.
The developed graphene sensors showed a mass-dependent frequency response shift of approximately 1 hertz per picogram on being bounded to the SARS-CoV-2 spike proteins. Finally, the graphene sensors demonstrated a limit of detection (LOD) as low as 2.63 picograms. The potential of FLIG platform technology was demonstrated in developing highly accurate graphene sensors with biological applications.
Graphene Sensors Towards the Detection of SARS-CoV-2 Spike Proteins
Graphene is a carbon allotrope that consists of a single sheet of carbon atoms arranged in a two-dimensional (2D) hexagonal lattice, where each atom shares with neighbors three in-plane σ-bonds and an out-of-plane π-bond.
Various techniques were previously reported for producing graphene. Recently, laser irradiation of a polymeric precursor to induce a photochemical and thermal conversion into graphene was added to the fabrication procedures. Graphene obtained in this way is usually called laser-induced graphene. The laser-induced graphene was applied in composites, gas sensors, soft actuators, and many more.
In most fabrication techniques, the laser-induced graphene remains embedded in the substrate, whose removal requires scraping, which either destroys the material’s structure or delaminates into the polymer and disturbs the morphology of the fabricated surface.
COVID-19 is a human infectious disease associated with severe respiratory distress caused by SARS-CoV-2, a single-stranded RNA-enveloped virus. SARS-CoV-2 spike proteins cover the surface of SARS-CoV-2 and bind to the host cell receptor angiotensin-converting enzyme 2 (ACE2), mediating viral cell entry.
The primary technique for diagnosing Coronavirus disease (COVID-19) is the reverse transcription-polymerase chain reaction (RT-PCR) technique. However, this is time-consuming, expensive, and requires professional personnel for operation. Recently, several detection platforms based on graphene sensors were reported for detecting SARS-CoV-2 spike proteins with high selectivity and low LOD
Laser-Induced Graphene Towards Detection of SARS-CoV-2 Spike Proteins
Resonative mass sensors are sensitive even to small masses. Upon binding of mass on these sensors, a frequency shift, which otherwise resonates around their fundamental frequency, is observed. Furthermore, reducing the resonator’s size can improve the sensor’s sensitivity due to its high response to small signals.
In the present study, a FLIG-based resonator was built as a resonative sensor with miniaturized dimensions along with high sensitivity and selectivity toward SARS-CoV-2 spike proteins and their quantification. The FLIG was functionalized with SARS-CoV-2 spike protein antibodies using a pyrene-containing linker that binds strongly to graphene and laser-induced graphene materials.
The functionalization of the graphene sensors with SARS-CoV-2 spike protein antibodies made them selective mass sensors. The functionalized graphene sensor was vibrated at the fundamental frequency initially, and upon binding of SARS-CoV-2 spike proteins, a change in resonance frequency was observed due to added mass.
Thus, FLIG sensors could indicate the existence of SARS-CoV-2 spike proteins and quantify the number of viruses present. The functionalized FLIG demonstrated excellent performance sensing an added mass of 2.63 picograms, calculated to be as few as approximately 5000 viruses.
Conclusion
Overall, the present work demonstrated the fabrication of ultrasensitive graphene sensors for detecting SARS-CoV-2 spike proteins. These graphene sensors were FLIG-based resonators whose mechanical properties and resonance response were outstanding for resonative sensors.
This detection process was optimized for sensing in liquid media. The FLIG was functionalized with COVID-19 antibodies that led to concentration-dependent changes in resonance frequency when exposed to SARS-CoV-2 spike proteins. The functionalized FLIG platform was highly porous and had a low-mass-density structure with exceptional performance sensing.
Moreover, FLIG was obtained at ultralow cost, and the operational principle of the corresponding sensor was simple. Thus, the FLIG technology was suitable as a sensing element in portable graphene sensors to detect viral proteins like SARS-CoV-2 spike proteins, which is an important strategy in pandemic management.
Due to the sensitivity of fabricated graphene sensors, SARS-CoV-2 spike proteins could be quantitatively estimated to obtain valuable information on the disease’s severity, stage, and contagion in patients.
News
Scientists Use Exotic DNA To Help Create “Climate-Proof” Crops
The incorporation of exotic DNA from wild relatives into wheat results in a remarkable yield increase of up to 50%, even in hot weather, surpassing elite lines without these genes. Amid a year of [...]
Australia becomes first country to recognise psychedelics as medicines
Australia has become the first country to recognise psychedelics as medicines, after the Therapeutic Goods Administration took researchers by surprise and approved the psychedelic substances in magic mushrooms and MDMA for use by people [...]
Silver nanoparticles show promise in fighting antibiotic-resistant bacteria
In a new study, scientists with the University of Florida have found that a combination of silver nanoparticles and antibiotics is effective against antibiotic-resistant bacteria. The researchers hope to turn this discovery into viable [...]
Combating severe cancer with a new drug delivery system
Peritoneal cancer is difficult to treat and has a poor survival prognosis. But a new and effective nanomedicine delivery system is offering some hope. The company is called NaDeNo and is well underway with [...]
New Research Shows How Ketamine Acts As “Switch” in the Brain
According to a new study by researchers at Penn Medicine, ketamine, which is well-known as an anesthetic and is becoming increasingly popular as an antidepressant, dramatically reorganizes activity in the brain, almost as if [...]
Supercharged T Cells: A New Way To Kill Pancreatic Cancer With Minimal Side Effects
A new immunotherapy releases cancer-killing cytokines only within the tumor. Researchers at the University of California San Francisco (UCSF) have developed a new T cell-based immunotherapy that selectively targets cancer cells, producing a powerful anti-cancer cytokine [...]
AI has designed bacteria-killing proteins from scratch – and they work
An AI was tasked with creating proteins with anti-microbial properties. Researchers then created a subset of the proteins and found some did the job. An AI has designed anti-microbial proteins that were then tested [...]
Using nanoparticles, researchers can identify and deliver synergistic combinations of cancer drugs
Treating cancer with combinations of drugs can be more effective than using a single drug. However, figuring out the optimal combination of drugs, and making sure that all of the drugs reach the right [...]
Humanity May Reach Singularity Within Just 7 Years, Trend Shows
By one unique metric, we could approach technological singularity by the end of this decade, if not sooner. A translation company developed a metric, Time to Edit (TTE), to calculate the time it takes for professional [...]
HYPER (Highly Interactive Particle Relics) – A New Model for Dark Matter
Phase transition in early universe changes strength of interaction between dark and normal matter. Dark matter remains one of the greatest mysteries of modern physics. It is clear that it must exist, because without [...]
New Nanoparticles Deliver Therapy Brain-Wide and Edit Alzheimer’s Gene
Summary: Researchers have developed a new family of nano-scale capsules capable of carrying CRISPR gene editing tools to different organs of the body before harmlessly dissolving. The capsules were able to enter the brains of [...]
Cancer’s Secret Weapon? Enzyme That Protects Against Viruses May Fuel Tumor Evolution
An enzyme that defends human cells against viruses can help drive cancer evolution towards greater malignancy by causing myriad mutations in cancer cells, according to a study led by investigators at Weill Cornell Medicine. The [...]
Scientists Uncover Japanese Fruit Juice That May Help Prevent Lung Cancer
Using a mouse model, Japanese researchers unleash the likely mechanism of action of Actinidia arguta (sarunashi) juice on lung cancer development. Lung cancer is a leading cause of death in Japan and across the [...]
In-place manufacturing method improves gas sensor capabilities, production time
When used as wearable medical devices, stretchy, flexible gas sensors can identify health conditions or issues by detecting oxygen or carbon dioxide levels in the breath or sweat. They also are useful for monitoring [...]
In the core of the cell: New insights into the utilization of nanotechnology-based drugs
Novel drugs, such as vaccines against covid-19, among others, are based on drug transport using nanoparticles. Whether this drug transport is negatively influenced by an accumulation of blood proteins on the nanoparticle’s surface was [...]
The costly lesson from COVID: why elimination should be the default global strategy for future pandemics
Imagine it is 2030. Doctors in a regional hospital in country X note an expanding cluster of individuals with severe respiratory disease. Rapid whole-genome sequencing identifies the disease-causing agent as a novel coronavirus. Epidemiological [...]
