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
New COVID-19 test quickly and accurately detects viral RNA
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 laboratory workhorse is showing signs of strain. Now, researchers reporting a proof-of-concept study in ACS Nano have developed a potentially more accurate diagnostic based on plasmonic photothermal sensing.
Health experts agree that expanded testing is crucial for controlling the spread of COVID-19. However, testing in many countries, including the U.S., has lagged behind because of limited supplies of some reagents and a backlog of samples awaiting available PCR machines and laboratory personnel. In addition, a number of false-negative and -positive test results have been reported. Other methods, such as computed tomography (known as "CT") scanning and culturing, do not provide quick or real time results. Jing Wang and colleagues wanted to develop a faster, potentially more accurate COVID-19 test for detecting the SARS-CoV-2 virus that could be a practical alternative to PCR.
The researchers based their test on a technique called localized surface plasmon resonance, which can detect interactions between molecules on the surface of a constructed metallic nanostructure as a local change in refractive index. The team made DNA probes that recognized specific SARS-CoV-2 RNA sequences and attached them to gold nanoparticles. When they added pieces of the virus's genome, the RNA attached to the complementary probes like a zipper being closed. The team used a laser to heat up the nanoparticles, making it more difficult for imperfectly matched sequences to remain attached, reducing false-positives. For example, a nucleic acid "zipper" missing a couple of teeth -- indicating a partial mismatch -- would unzip under these conditions. In this way, the researchers could discriminate between SARS-CoV-2 and its close relative, SARS-CoV-1. The assay detected amounts of viral RNA below those present in respiratory swabs in a matter of minutes. Although the test still needs to be tested on intact viral RNA from patient samples, it could help relieve the current pressure on PCR-based tests, the researchers say.
- surface plasmon resonance
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, resea ... 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
A team of researchers from Empa, ETH Zurich and Zurich University Hospital has succeeded in developing a novel sensor for detecting the new coronavirus. In future it could be used to measure the concentration of the virus in the environment - for example in places where there are many peopl ... more
ETH physicists have developed the first high-repetition-rate laser source that produces coherent soft x-rays spanning the entire ‘water window’. That technological breakthrough should enable a broad range of studies in the biological, chemical and material sciences as well as in physics. ... more
They should be fast, portable and easy to use: blood tests that can be done at home. Having already come up with a prototype, ETH Pioneer Fellow Alexander Tanno is working with doctoral student Yves Blickenstorfer to bring the idea to market. The prototype that Alexander Tanno is holding be ... 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