Within the framework of a project funded by Carlos III Health Institute (Carlos III Health Institute), the project solved the crisis caused by the COVID-19 pandemic. graduate School IMDEA Nanoscience The Autonomous Community of Madrid has received assistance in the following areas: 340.000 euros Develop one New test The specific sequence of coronavirus RNA can be detected in a simple manner without the need for as many resources as other diagnostic methods.
As a sensor for pathogens, the technology uses Gold nanoparticles Where they anchored DNA strand, Able to detect a specific sequence gen RdRP Exist in SARS-CoV-2 virusAnd the E gene shared by all coronaviruses.
The test consists of a vial containing an aqueous solution, which is red in color due to the presence of tiny gold particles. When the coronavirus RNA is incorporated, these DNA-functionalized nanoparticles will aggregate and precipitate to the bottom, thereby significantly reducing the color of the solution. It can be seen with the naked eye.
As the researchers explained Alvaro SomozaResearch team leader: “The DNA strand of the nanoparticle is folded into a hairpin shape with a hydrophobic group (cholesterol) at the end. In this case, the structure is soluble in water.”
“However, in the presence of viral RNA, the DNA of the nanoparticle binds to the sequence of the virus. Experts clarified Sinc, the hairpin was opened, and cholesterol was exposed to the medium, resulting in the production of insolubles. “The structure in the water and causes the nanoparticles to precipitate. “As a result, the solution became colorless.
Colorimetric test protocol, which is based on the combination of gold nanoparticles and DNA. /IMDEA Nanoscience
So far, researchers have not used real samples of the coronavirus, but have used models and sequences similar to pathogen RNA, including synthetic copies of the RdRP gene. When the prototype is ready, ISCIII scientists will test it using sequences from real viruses, first attenuating it, and then directly using samples from infected patients.
The idea is in Three amplification systems Or perform diagnosis or diagnosis at the same time to reduce the use of equipment, highly specialized personnel and required reagents.
On the one hand, it will be used with reverse transcriptase (Reverse transcription PCR), which is a variant of PCR used in molecular biology to generate large numbers of copies of genetic material. This process is called amplification.
In this way, there is no need to use the so-called qRT-PCR, that is, fluorescent compound labeling. Although it has advantages such as simultaneous detection of many targets in each sample, it requires costly optimization and design of specific fluorescent compounds. Probe.
On the other hand, the method will also be Isothermal amplification, Without using PCR, and you only need a small multifunctional laboratory unit called Thermoblock, and Non-enzymatic amplification, Which does not use any enzymes, and the sample preparation is minimal.
Used in hospitals and health centers
According to its sponsor, the implementation of this technology will be implemented quickly and easily in current diagnostic procedures and can be used in hospitals and health centers.Professionals can observe the color change in the sample bottle A few hours later.
The research center has been able to prepare nanoparticles, DNA and other oligonucleotides (its sequence is the same as that of virus RNA, but due to stronger interaction and better response, it can be prepared in DNA) and small-scale nitrocellulose strips . .
For mass production, they need more resources and equipment, but IMDEA Nanoscience can produce Approximately 5,000 sensors per week Through an industrially scalable process.
According to the person in charge and chief researcher of the entire project, Rodolfo Miranda“We hope to be able to contribute to the fight against this pandemic by realigning an important part of the Institute’s multidisciplinary capabilities to achieve efficient and easy-to-use testing.”
Various tests to identify the new coronavirus quickly or through PCR have become an indispensable measure to understand the scope of this health crisis and to counter it. By identifying carriers with or without symptoms, you can isolate them and prevent the spread of epidemics.
Experts believe that it is necessary to evaluate a large proportion of the population and repeat these studies for several weeks, because the virus can spread from person to person between a few days (if present) when symptoms first appear and three weeks after infection. .