Today, biosensors are becoming increasingly important in many areas of human activity: in medicine (for example, to measure blood sugar and other metabolites in blood), agriculture, food industry, etc. In the near future, they will become indispensable, in particular, they will help to monitor all important indicators of the human body in real time.
We asked Oleksii Soldatkin, Head of the Department of Biomolecular Electronics at the Institute of Molecular Biology and Genetics of the NASU, Academician of the National Academy of Sciences of Ukraine, Chairman of the Section of Biology, Medicine and Agricultural Sciences of the NRFU, to tell about the capabilities of biosensors and how Ukrainian science has progressed in this area. Oleksii Soldatkin is one of pioneers of Ukrainian biosensing, together with members of the research team he designed dozens of biosensor devices and received almost fifty patents.
We have to admit that we expected to see half-empty corridors (because of the war many researchers work remotely), but we were met by a group of young people. The early career researchers sought to demonstrate the most interesting areas of work (and each area was, of course, the most important), showed us experiments, sensors, and told us how and where all this could be applied in practice (from a trip to Mars to everyday life). The head of the department looked at his enthusiastic colleagues with pride and, if a spectacular experiment did not work, asked if they understood the reason and advised them to repeat it.
– Professor Soldatkin, today you are one of the most famous researchers in the field of biosensing, the founder of the Ukrainian scientific school of biosensing, and the developer of a number of bioanalytical devices. Tell me, please, when you graduated from Taras Shevchenko National University of Kyiv and came to the Institute, what did you dream of? What did you want to achieve?
“You are exaggerating my role in the development of biosensing in Ukraine a bit”, he smiled. “I was very lucky to have a mentor – Academician of the National Academy of Sciences of Ukraine Hanna Yelska – who lectured at the university and invited me to work. It was Hanna Yelska, together with Professor Vitaliy Strikha, who initiated the development of biosensors in Ukraine. Once, Hanna Yelska called me and said: “If you want to grow as a scientist, start working in a new direction.” I agreed and headed the biosensor development group.
The decades that have passed since that day have not been easy. But now my department has four Doctors of Sciences, one Correspondent Member of the National Academy of Sciences of Ukraine, eight PhDs, and a lot of early career researchers. A number of biosensor developments of our group have no analogues in the world, and the department itself is one of the world leaders in the field.
When I was a student, I did not even dream of such achievements. I started working at the Institute in 1977, defended my PhD thesis in 1985 in Molecular Biology. In 1999, I defended my doctoral dissertation in Biotechnology. It was the first doctoral dissertation in biosensing in Ukraine.”
– Could you please explain in the simplest terms possible what biosensors are?
“Biosensors are state-of-the-art analytical devices that contain a “living” biological material (which “recognizes” substances and generates a biochemical signal) and a physical transducer (which receives a biochemical signal and converts it into an electrical one). The electrical signal is the measure of the substance concentration being analyzed. The most well-known biosensor is the blood glucose sensor, the so-called glucometer. But, of course, various biosensors can be used in almost all areas of human activity.”
– Your department develops chemosensors and biosensors for various purposes, in particular, for environmental pollution monitoring. Today, in times of war, this is especially important because the enemy uses poisonous substances… Have you managed to introduce environmental pollution monitoring devices into production?
“Yes, we have developed biosensors for the inhibitory determination of heavy metal ions (mercury, lead, cadmium, copper, etc.) and organophosphorus compounds (some pesticides and herbicides).
These sensors can be used to measure the level of herbicides and heavy metal ions in water bodies.
By the way, virtual maps are currently being created abroad to show the data from sensors that are planned to be installed near riverbanks close to potentially harmful industries. When toxic substances leak, the sensors will signal the danger and an alarm will be activated on the map. In fact, our department was once involved in such a project.
We also participate in one of the projects of the Horizon Europe program. At the request of a textile company from Turkey which wants to control the level of heavy metals during fabric dyeing we are developing biosensors for closed-loop water quality monitoring.
We have developed dozens of biosensors. We have created laboratory models and tested their effectiveness on real samples. Methods for the use of biosensor devices have been developed and approved by the state enterprise “Ukrmetrteststandard”. However, these developments have not yet been implemented in manufacturing. In order to do this, significant investments are needed in licensing, setting up a production line, etc.
Both in Ukraine and globally, developments implementation is a complex and expensive business. If we compare time and financial support required to develop and implement a biosensor, the ratio is 10 to 90 percent. Unfortunately, there is still no system for implementing research in Ukraine.”
– One of the areas of your department’s work is the identification of toxins in food and food quality control. Please tell us more about these developments.
“With the start of the full-scale invasion in Ukraine by russian troops, the issue of food security in the world has become particularly acute, since Ukraine used to supply grain to many countries. The production and supply of grain, in turn, is linked to the control of its quality. Grain analysis needs to be carried out quickly and properly, both at the place of production and during storage and transportation.
Today, contamination of grain, food and animal feed with mycotoxins – toxic and carcinogenic metabolites of the lower fungi Aspergillus and Fusarium – is a global problem that ‘accompanies’ grain during cultivation, storage and sale. Consumption of contaminated products by humans or animals can have significant health consequences and, thus, economic losses.
Researchers of our department have developed a number of modern biosensor methods for detecting the most common and toxic mycotoxins in grain – aflatoxins of group B and zearalenone. These methods allow detecting toxins in the smallest amounts.
We have also proposed a new approach to the creation of biosensors, namely the synthesis of highly stable artificial analogs of biological receptors (biomimetic polymers). We have developed a new generation of sensors including the ones that can be used as detectors and analyzers of sensor signals in smartphones.
We have also optimized the composition of mycotoxin-specific polymers. We use computer modeling methods (molecular dynamics, quantum chemical methods) to produce materials with predictable properties. These materials ‘bind’ the target mycotoxins, generate optical sensory signals, which, in turn, are easily ‘caught’ by a smartphone camera. The mobile application for Android 6+ analyzes these signals.
The analysis procedure is simple: the application is installed on the smartphone with one click. Once installed, the device for mass analysis of grain samples outside the laboratory is ready.
Another very interesting device we have developed is a biosensor for analyzing glycoalkaloids in vegetables (potatoes, tomatoes, eggplants). The analysis is simple, it does not require complex sample preparation, and takes 15-20 minutes. Traditional analysis using high-performance liquid chromatography requires tens of hours of sample preparation, sophisticated equipment, and qualified personnel.”
– The pioneering development of your department’s researchers is a biosensor for quantitative detection of arginine in food products. What are the advantages of this sensor compared to traditional methods of arginine detection?
“Arginine is an essential amino acid which is one of the key nutritional biologically active substances. It helps to restore many body functions and is increasingly used for therapeutic and rehabilitation purposes. The participation of arginine in the synthesis of nitric oxide (necessary for blood pressure regulation, good memory, etc.) is very important, so in medical practice increased doses of arginine are used to treat and prevent diseases caused by nitric oxide deficiency. Arginine therapy is used in the treatment of atherosclerosis, hypertension, liver diseases, etc.
One of the ways to correct nutritional deficiency of this substance is to use special food products that have a high content of L-arginine. There are hundreds of such products on the market today, and consumers need to know how effective and safe they are. Quality control of dietary supplements and specialty foods for arginine content is a task for independent expertise.
You can determine the amount and quality of arginine in foods using traditional methods (there are many of them in laboratory practice), but all of these methods are imperfect. Some require a large amount of material for analysis and are not sensitive enough. More precise and selective methods require long sample preparation and are too expensive for routine use.
That is why the development of biosensors for arginine detection, adapted for use both in centralized laboratories and in the field, is very important for quality control of products intended to maintain health or meet the acute need for arginine.
The sensor we have developed is not yet universal. It can measure the level of the amino acid in foods and control the quality of pharmaceutical samples.
We cannot measure the level of arginine in the body yet, but we are working hard in this direction. We also want to improve the characteristics of the biosensor using calixarenes, artificial receptors created at the Institute of Organic Chemistry of the National Academy of Sciences of Ukraine (headed by Academician Vitalii Kalchenko). We plan to create a device that will help measure arginine (and not only this amino acid) in human blood.”
– Your department is developing a device for diagnosing the severity of patients with polytrauma. Before the pandemic, the researchers of the Institute of Molecular Biology and Genetics of the National Academy of Sciences of Ukraine had received a state order to develop this system. Were the funds allocated? Did you manage to complete the research?
“Yes, our department is indeed developing such a device and its importance cannot be overestimated. When an ambulance takes a person with polytrauma, very often their condition needs to be assessed immediately, on the way to the hospital. Our device will help to do this, and it can be used by combat medics, emergency doctors and inpatient department doctors right at the patient’s bedside.
The device is based on a simple methodology for determining the ratio of lactate and pyruvate in the blood serum. This biosensor system can be implemented not only in Ukraine but also in other countries. It will help reduce the time for diagnosis and significantly improve the effectiveness of patient treatment.
In 2020, the Institute of Molecular Biology and Genetics of the NASU did receive a government’s order for the development and implementation of this system, but unfortunately, we did not receive funding (due to the coronavirus pandemic and a government decision that prohibited advance payment and allowed allocating funds only for work already performed).
Currently we have decided to take advantage of the second chance to develop and implement an important and economically profitable biosensor device for determining the lactate/pyruvate ratio in everyday clinical diagnostics. The staff of the department submitted the project to the NRFU call “Science for the Recovery of Ukraine in the War and Post-war Periods”.”
– Researchers in your department are also creating new biosensors based on nanomaterials. Why is this important?
“By using nanomaterials we can adapt those characteristics of sensors we need for our purposes.
With the help of nanoparticles of different nature important analytical characteristics of sensors can be controlled and targeted. We are talking about such characteristics as stability (operational and during storage), analysis time, sensitivity and linear operating range, etc. With this approach, we can control the operating characteristics of biosensors and adjust them to the appropriate conditions of use. To put it simply, the whole structure of the study is changing. Previously, we tested different materials and found promising ones for creating biosensors, but now using nanomaterials we set the necessary characteristics of biosensors from the very beginning and set the appropriate testing conditions.
We also use genetically modified enzymes. The active center of such an enzyme can be modified to meet a specific need. For example, the use of recombinant urease allowed us to expand the range of urea determination in the patient’s blood tenfold (covering both norm and pathology).
By the way, we want to expand the range of compounds that can be determined by biosensor methods. Therefore, we work with complex multi-enzyme systems. They make it possible to expand the range of analyte substances.”
– How did the war affect your research plans? What are you working on today?
“Of course, the war has greatly affected our work. Several talented young female employees of the department temporarily left the country. We hope they will return. The team of the department has been built up over the years, and a lot of effort has been put into training early career researchers. I do not want the situation of the nineties to repeat itself, when young people (for various reasons) left science…
I also deliver lectures at the Institute of High Technologies of Taras Shevchenko National University of Kyiv. Employees of the department deliver courses at Kyiv-Mohyla Academy and Igor Sikorsky Kyiv Polytechnic Institute. I am glad that many talented young people are studying in institutions of higher education. I hope that graduates of these universities will come to our institute for postgraduate studies. We have a very good and professional team and extremely promising research.
In the future, biosensors will be indispensable in all spheres of life, perhaps even toothbrushes will be equipped with sensors”, he smiled. “Being involved in their development is a great privilege for a researcher.”
Interviewed by Svitlana Galata
