More than 100 years ago, police investigators began using fingerprints to help track down criminals. Today, other researchers - chemists - are developing molecular "fingerprints" to help sensors track viruses and other wanted objects.
One such chemist is Raimonda Bogužaitė, a PhD student of the Department of Nanotechnologies. On 18 October, she won Tyrėjų Grand Prix 2023, a unique competition for young scientists in Lithuania. Her presentation on molecular imprinting in sensors was gripping from the very first seconds.
Congratulations to our dear Colleague!
„I would like to thank all my collaborators who have contributed to my PhD, and everyone I have worked with. Without these people I would not have had my presentation. Because our work is a team effort,“ says Raimonda.
(Raimonda Bogužaitė. Photo: FTMC)
The event at the Grand Hotel Kempinski Vilnius is also known as the "X Factor" for scientists, as participants try to present their PhD thesis topic in the most attractive and understandable way possible. They have four minutes on stage to do so. Each presentation is commented on by a jury and the audience votes to choose the winner.
According to the organisers, the aim is to connect science and entertainment and to bring the latest research and discoveries to the public. Tyrėjų Grand Prix 2022 was initiated by investor Žaneta Freyer, whose idea was implemented today by the Lithuanian Society of Young Researchers.
FTMC chemist R. Bogužaitė presented the topic about development of electrochemical sensor based on polypyrrole and modification of its properties. According to the scientist, she and her colleagues are looking for solutions to develop a sensor based on molecular imprinting technology. These imprints are based on the chemical material polypyrrole.
It may sound complicated, but we'll explain soon.
(Raimonda Bogužaitė. Photo: FTMC)
Space for a missing puzzle piece
Remember the fairy tale of Cinderella? The Prince found a shoe and rushed to find its owner. Many girls tried on the shoe - it was too wide, too tight - until finally Cinderella came along, and the shoe fit her perfectly. The Prince recognised that this was the beautiful girl he had fallen in love with at the party.
Now, let's imagine we're not looking for Cinderella, but for, say, a virus molecule. Scientists are trying to create "shoes" that will allow us to accurately identify pathogens or other desired objects.
Another example: we have a jigsaw puzzle with a missing piece in the middle. There is a bunch of different pieces, of which only one will fit. Similarly, in the laboratory, we make the right complex chemical base with a "hollow shape" and see if any molecule will "fit" nicely into it.
Finally, let's remember the fingerprints (which Raimonda mentioned in her competition presentation). With these samples, you can determine whether the neighbour you accused really broke into your flat. Something similar with the technology being developed by FTMC researchers.
(Simplified molecular imprinting technology flowchart. Illustration by Raimonda Bogužaitė)
How is this done?
Chemists here work with molecules. One molecule is chosen as a template, and other molecules - monomers - are released to "float" around it. These, when exposed to radiation, heat or other methods, "stick together" to form a polymer. This new formation then 'sticks' to the template.
Then the template molecule is removed (chemically washed away) and we have a molecular imprint, like an irregularly shaped donut with an empty cavity. Now we just need to attach the "donut" to the biosensor and use it in different samples. If, for example, a molecule appears in a liquid that perfectly matches the shape of the imprint, then the person has a disease, or something like that. The practical applications are many.
Searches for "lock and key"
It may sound simple, but accurate molecular imprinting requires a lot of work and patience:
"Research on this technology has been going on for a number of years. We have a number of success stories, such as our experiments with the COVID-19 needle protein detection. However, when creating a molecular imprint, there is often a success factor, whether you wash the molecule right, whether you precipitate the polymer layer, whether you get the result you need. There is no one definitive recipe."
(Raimonda Bogužaitė with her friends and colleagues. Photo: FTMC)
However, the researcher notes that the methodology holds great promise for applications in a wide range of detection systems, such as medical diagnostics, food safety screening or environmental monitoring.
"The biggest advantage is the complementarity between the analyte and the imprinted polymer, i.e. the spatial correspondence of the molecules. It's like a key that matches a lock. As a result, such a sensor is likely to be more selective, able to distinguish and identify the analyte of interest.
The methodology is straightforward and can be replicated more cheaply (hopefully) and quickly. And it's more cost-effective," says Raimonda Bogužaitė.
"This is the second edition of Tyrėjų Grand Prix. The winner of the first contest in 2022 was another FTMC representative, physicist Karolina Maleckaitė, who presented her research on how glowing molecules help determine the viscosity of cells. She later successfully defended her PhD thesis on this topic.
Written by Simonas Bendžius