A team led by an Indian-origin scientist has developed a rapid, ultrasonic-COVID-19 test using a paper-based electrochemical sensor that detects the presence of novel coronaviruses in less than five minutes Can.
Researchers at the University of Illinois in the US built a graphene-based electrochemical biosensor with an electric read-out setup, which selects the presence of SARS-CoV-2 genetic material.
According to research published in the ACS Nano Journal, this biosensor has two components: a platform for measuring electrical read-outs and probes to detect the presence of viral RNA.
To build the platform, the researchers led Professor Dipanjan Pan first coated filter paper with a layer of graphene nanoplates to make a conductive film.
They then placed a gold electrode with a predefined design on top of the graphene as a contact pad for electrical readout.
The researchers said that gold and graphene have both sensitivity and conductivity, which makes this platform ultrasonic to detect changes in electrical signals.
“Graphene exhibits unique mechanical and electrochemical properties that make it ideal for the development of sensitive electrochemical sensors,” said Maha Alfieff, a graduate student at the Illinois Gringer College of Engineering. “
They stated that RAS-based COVID-19 tests for the presence of the N-gene (nucleocapsid phosphoprotein) on SARS-CoV-2 viruses.
In new research, the team designed antisense oligonucleotide (ASO) probes to target two regions of the N-gene.
According to the researchers, in the case of one region undergoing gene mutation, targeting two regions ensures the reliability of the sensor.
Gold nanoparticles (AuNPs) are capped with these single-stranded nucleic acids (ssDNA), representing a hyper-sensitive sensing probe for SARS-COV-2 RNA.
The team tested the performance of this sensor using COVID-19 positive and negative samples.
The sensor showed a significant increase in the voltage of positive samples compared to negative samples and confirmed the presence of viral genetic material in less than five minutes.
The sensor was able to isolate viral RNA loads in these samples. Viral load is an important quantitative indicator of infection progression and is a challenge to be measured using existing diagnostic methods.
Researchers noted that this platform has far-reaching applications due to portability and low cost.
The sensor, when integrated with a smartphone with a microcontroller and LED screen, or via Bluetooth or WiFi, can be used in a doctor’s office or even at home.
Beyond COVID-19, the research team also confirms the system of being adaptable to detect many different diseases.
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