To defend the body, the immune system makes proteins known as antibodies that latch onto the perceived threat, be it HIV, the new coronavirus or, as is the case in autoimmune disease, part of the body itself. In a new proof-of-concept study in ACS Sensors, researchers describe a new system ... more
Diagnostic biosensor quickly detects SARS-CoV-2 from nasopharyngeal swabs
New test analyzes patient samples without any sample preparation steps
According to many experts, early diagnosis and management are critical for slowing the spread of SARS-CoV-2, the new coronavirus that causes COVID-19. Therefore, the race is on to develop diagnostic tests for the virus that are faster, easier and more accurate than existing ones. Now, researchers reporting in ACS Nano have developed a field-effect transistor-based biosensor that detects SARS-CoV-2 in nasopharyngeal swabs from patients with COVID-19, in less than one minute.
Currently, most diagnostic tests for COVID-19 rely on a technique called real-time reverse transcription-polymerase chain reaction (RT-PCR), which amplifies SARS-CoV-2 RNA from patient swabs so that tiny amounts of the virus can be detected. However, the method takes at least 3 hours, including a step to prepare the viral RNA for analysis. Edmond Changkyun Park, Seung Il Kim and colleagues wanted to develop a faster diagnostic test that could analyze patient samples directly from a tube of buffer containing the swabs, without any sample preparation steps.
The team based their test on a field-effect transistor -- a sheet of graphene with high electronic conductivity. The researchers attached antibodies against the SARS-CoV-2 spike protein to the graphene. When they added either purified spike protein or cultured SARS-CoV-2 virus to the sensor, binding to the antibody caused a change in the electrical current. Next, the team tested the technique on nasopharyngeal swabs collected from patients with COVID-19 or healthy controls. Without any sample preparation, the sensor could discriminate between samples from sick and healthy patients. The new test was about 2-4 times less sensitive than RT-PCR, but different materials could be explored to improve the signal-to-noise ratio, the researchers say.
- field effect transistors
- diagnostic tests
Millions of people have been tested for the novel coronavirus, most using a kit that relies on the polymerase chain reaction (PCR). This sensitive method amplifies SARS-CoV-2 RNA from patient swabs so that tiny amounts of the virus can be detected. However, as the pandemic surges, this labo ... more
After a day hiking in the forest, the last thing a person wants to discover is a tick burrowing into their skin. Days after plucking off the bloodsucking insect, the hiker might develop a rash resembling a bull's-eye, a tell-tale sign of Lyme disease. Yet not everybody who contracts Lyme di ... more
The products we use every day leave behind chemical footprints. Learn how and why researchers are now studying those trails. Mass spectrometry is helping researchers learn more about our interactions with the everyday chemicals we use, such as DEET, caffeine, even medications. In this episo ... more
- 1New Indication of a Link Between Alzheimer’s and Diabetes
- 2Click... Resistant bacteria caught in the act!
- 3Nanosafety research without animal experiments
- 4The relationship of proteins
- 5Could the blood of COVID-19 patients be used to predict disease progression?
- 6DKSH extends partnership with Bruker in China
- 7Detecting antibodies with glowing proteins, thread and a smartphone
- 8RNA structures by the thousands
- 9Developing new techniques to improve atomic force microscopy
- 10Snapshot of exploding oxygen