Washington:
A group led by an Indian-origin scientist has created a speedy, ultrasensitive COVID-19 test applying a paper-primarily based electrochemical sensor that can detect the presence of the novel coronavirus in much less than 5 minutes.
The researchers from the University of Illinois in the US produced a graphene-primarily based electrochemical biosensor with an electrical study-out setup to selectively detect the presence of SARS-CoV-2 genetic material.
According to the analysis published in the journal ACS Nano, there are two elements to this biosensor: a platform to measure an electrical study-out and probes to detect the presence of viral RNA.
To make the platform, the researchers led by professor Dipanjan Pan very first coated filter paper with a layer of graphene nanoplatelets to make a conductive film.
They then placed a gold electrode with a predefined style on leading of the graphene as a speak to pad for electrical readout.
Both gold and graphene have higher sensitivity and conductivity which tends to make this platform ultrasensitive to detect adjustments in electrical signals, the researchers noted.
“Graphene exhibits unique mechanical and electrochemical properties that make it ideal for the development of sensitive electrochemical sensors,” stated Maha Alafeef, a graduate student at the University of Illinois Grainger College of Engineering.
Current RNA-primarily based COVID-19 tests screen for the presence of the N-gene (nucleocapsid phosphoprotein) on the SARS-CoV-2 virus, they stated.
In the new analysis, the group created antisense oligonucleotide (ASOs) probes to target two regions of the N-gene.
Targeting two regions guarantees the reliability of the sensor in case one particular area undergoes gene mutation, according to the researchers.
The gold nanoparticles (AuNP) are capped with these single-stranded nucleic acids (ssDNA), which represents an ultra-sensitive sensing probe for the SARS-CoV-2 RNA.
The group tested the overall performance of this sensor by applying COVID-19 positive and unfavorable samples.
The sensor showed a substantial boost in the voltage of good samples compared to the unfavorable ones and confirmed the presence of viral genetic material in much less than 5 minutes.
The sensor was capable to differentiate viral RNA loads in these samples. Viral load is an crucial quantitative indicator of the progress of infection and a challenge to measure applying current diagnostic approaches.
The researchers noted that this platform has far-reaching applications due to its portability and low price.
The sensor, when integrated with microcontrollers and LED screens or with a smartphone by means of Bluetooth or wifi, could be employed at the point-of-care in a doctor”s workplace or even at house, they stated.
Beyond COVID-19, the analysis group also foresees the technique to be adaptable for the detection of numerous various ailments.
()