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- Strict sensor: graphene sensor will detect herpes virus in 1.5 minutes
Strict sensor: graphene sensor will detect herpes virus in 1.5 minutes
Russian scientists have created a compact device that detects one of the most common types of herpes virus in just 1.5 minutes. Such diagnostics do not require sophisticated equipment and specially trained personnel, unlike the currently used laboratory PCR studies. According to experts, the development can be used in polyclinics and hospitals. However, for this, the device needs to be improved so that it can detect other types of herpes virus.
A quick herpes test
Researchers at Moscow Polytechnic University, together with colleagues from Lomonosov Moscow State University and institutes of the Russian Academy of Sciences, have created a flexible graphene sensor that detects the protein of the herpes simplex virus type I in just 1.5 minutes. Currently, this requires laboratory PCR analysis using an amplifier and the participation of specially trained personnel.
The developers have manufactured and tested 15 sensors. All of them reacted to the virus protein, and the strength of the response increased along with its concentration. To test the selectivity of the sensors, the scientists also tested them on albumin, one of the most common blood proteins. The response to the virus protein was about nine times stronger. The minimum concentration at which the signal was detected was about 100 picomoles per liter, which is one trillionth of a mole per liter.
So far, the experiments have been carried out in laboratory conditions on purified protein in a buffer solution. Before using the technology in medical diagnostics, it will have to be tested on real biological samples, such as saliva, and also to check how other proteins that can interfere with measurements affect the results.
— The next stage is testing with real samples. In parallel, we are developing this area to measure neurotransmitters, primarily dopamine and serotonin. Changes in their levels are associated with a number of diseases, including Parkinson's disease. Therefore, a quick way to track their concentration would be useful for researchers and doctors," said Ivan Komarov, project manager, senior researcher at the Automated Technical Systems Scientific and Technical Center at Moscow Polytechnic University.
According to WHO, about 3.8 billion people under the age of 50 worldwide are infected with the herpes simplex virus of the first type. This is approximately 64% of the population in this age group. Since the virus remains in the body for life, the proportion of infected people over the age of 50 is even higher. After initial infection, the virus remains latent in the body and, under certain conditions, can be reactivated, sometimes even without visible symptoms. Most often, the infection is manifested by rashes on the lips, but severe complications are also possible: eye damage, encephalitis, and infection of newborns.
The researchers obtained thin films of graphene oxide on a flexible polymer substrate. Laser treatment removes some of the oxygen-containing groups, which increases the electrical conductivity of the material. At the same time, areas with different properties are formed within the same film: the contacts are treated more intensively, and the sensitive area is treated more gently. This makes it possible to preserve on its surface the chemical groups necessary for the fixation of recognizing molecules. The size of the finished sensor is about 15 mm.
To recognize the protein, the researchers used aptamers, short DNA strands that selectively bind to a specific molecule. The selected aptamer binds to glycoprotein D, a protein on the surface of the virus that allows it to enter human cells. The interaction with the protein causes a change in the electrical resistance of the film, which is recorded by the measuring system, said Ivan Komarov.
Implementation in practice
The development looks promising, but it is still at an early, laboratory stage. Its main advantage may be speed and ease of use, according to Leonid Drobyshevich, NTI technology expert.
— Such a test is unlikely to be able to replace PCR, but it has an understandable niche. This is a quick initial check where there is no laboratory nearby or the result has to wait a long time: in polyclinics, ophthalmology rooms, maternity hospitals, as well as in field and rural medicine. Such a diagnosis is especially important for patients who may have severe herpes," he said.
A quick test could be useful for pregnant women before giving birth, as well as for suspected herpetic eye damage, when delay threatens to cause vision loss. If the effectiveness of the sensor is confirmed on real samples, it can become a convenient tool for screening and monitoring these groups of patients, the specialist emphasized.
The development may be of significant interest to both medicine and business, says Maxim Kolyasnikov, a leading researcher at the Bauman Moscow State Technical University's Functional Micro/Nanosystems Scientific and Educational Center.
— PCR tests for herpes can take up to several working days, while the new sensor gives a very fast response. However, so far it has been tested only on purified protein in solution. At the same time, it is already obvious that highly qualified personnel will not be required to work with it. The full time for the analysis of patient samples has yet to be determined," said Maxim Kolyasnikov.
As the expert emphasized, so far the researchers have worked only with the protein of the herpes simplex virus of the first type, however, there are other types of the virus. To commercialize the development, it is necessary to confirm its accuracy on real samples, test the ability to detect other types of virus and, most importantly, distinguish between them.
Переведено сервисом «Яндекс Переводчик»
