Greetings dear readers, continuing with the same line of work, today I am going to share with you some innovative information regarding the continuous advances that are being made in this subject that worries and concerns us all, I am talking about Covid-19 and its detection in record time, through the use of biosensors.
Biosensors are a rapid analysis device, which works with biological material in this specific case will be with nucleic acid and detects and interprets the complementary sequences of single strands of DNA or RNA, through the use of a genosensor or DNA sensors, which allows an easy, selective and inexpensive analysis..
Currently, physicist Osvaldo Novais de Oliveira, in charge of a multidisciplinary group of researchers in Brazil, has manufactured a device of this type, with the aim of corroborating its efficacy in detecting SARS-CoV-2.
The results of this test are obtained in a record time of thirty minutes (30min) and at a very low cost. This technology is already available to any laboratory or company that meets the fundamental requirements for large scale reproduction.
In this test, the function of the genosensor is to capture the immobility of the DNA single strand, through a process called hybridization, in which the immobile DNA strand will be joined by a complementary process of its bases to another DNA strand, which is found in the liquid sample to be analyzed. With this process, the presence of SARS-CoV-2 can be evidenced in body fluid or saliva samples.
Basically the function of the device is to immobilize the single stranded DNA and RNA used in the capture sequence, if hybridization with the complementary helix is identified in the sample, a change in physical parameters will be observed, which is determined by electrical impedance spectroscopy and plasmon resonance..
The shift of the absorbance peak in the transmitted spectrum that is monitored by using localized surface plasmon resonance with the utility of a spectrophotometer is one of the effects of the hybridization that originates between the capture sequence and the complementary sequence of Covid-19.
The sensitivity obtained in the study of the detection of the DNA sequence in body fluids and saliva, in addition to the determination of the complementary helices of the virus, was achieved with the application of a machine learning strategy on scanning electron microscopy images obtained with the DNA sensors. By applying the corresponding algorithms in the imaging process, a high accuracy in the concentrations of the complementary DNA sequences of the virus was achieved.
During the development of the tests for the detection of SARS-CoV-2, the genosensors were tested with control samples, which had negative sequences for the virus and the other DNA biomarkers that have no relationship with the new coronavirus. The results obtained with the application of the corresponding technique called multidimensional projection (IDMAP) were analyzed, resulting in an evident separation of the complementary DNA sequences in their different concentrations, as well as in the samples that did not contain the SARS-CoV-2 virus.
Undoubtedly there are many methods of detection of Covid-19 that are currently being used and which will depend on the place or each country in the world in which these tests are done, however the DNA sensor or genosensor is the most innocuous device for the detection of the new SARS-CoV-2 variants. For this, it is only necessary to identify the genetic sequence of this variant or new strain and modify the single strand of DNA used as the capture sequence.
MATERIAL CONSULTED
D’Suze García, Carlos. (2021). Antigenic testing in epidemiological surveillance of Covid-19. Source:
Díaz Jiménez, Irma Virginia. (2020). Interpretation of diagnostic tests for SARS-CoV-2 virus. Source:
World Health Organization (WHO). (2021). Update on COVID-19 testing strategies. Latest developments on COVID-19 in the world and how to use testing to achieve public health goals.. Source:
