Biosensor Sensitivity Enhanced Considerably by Moscow Institute Physicists

February 24, 2020 by Luke James

Moscow physicists may be closer to bringing to reality biosensors that are integrated into smartphones and other consumer electronics.

This is according to recent research which was funded by the Russian Science Foundation and published in the January issue of Sensors. In their publication, the researchers describe a way to increase the sensitivity of biosensors to the point where they can be used in consumer electronic devices such as smartphones and wearables. 


Making Biosensors More Sensitive

Until this point, biosensors have never really been considered for use in consumer electronics. This is because the biosensor devices that existed were simply not sensitive enough and were far too expensive for the consumer market. 

However, the new biosensor design created by the researchers at the Moscow Institute of Physics and Technology Center for Photonics and 2D Materials could increase detector sensitivity several times over while also dramatically reducing the price.

"A conventional biosensor incorporates a ring resonator and a waveguide positioned in the same plane," explained MIPT graduate student Kirill Voronin from the Laboratory of Nanooptics and Plasmonics, who came up with the idea used in the study. "We decided to separate the two elements and put them in two different planes, with the ring above the waveguide."

This, as the researchers call it, is a two-level sensor layout. It was achieved by depositing a thin film and etching it, which creates both a ring resonator and waveguide at the same time and resulted in a higher sensitivity. Although this two-level design is less convenient for manufacturing unique devices, it is cheaper for mass-producing sensors. More importantly, however, is that the new two-tier design resulted in sensitivity many times higher than current biosensors. 

"We have positioned the strip waveguide under the resonator, in the bulk dielectric," said paper co-author Aleksey Arsenin, a leading researcher at the MIPT Laboratory of Nanooptics and Plasmonics. "The resonator, in turn, is at the interface between the dielectric substrate and the external environment. By optimizing the refractive indices of the two surrounding media, we achieve a significantly higher sensitivity."


A biosensor layout provided by the Moscow Institute of Physics and Technology.

A diagram layout of the biosensor used by Moscow Institute researchers. Image used courtesy of Kirill Voronin


Using Biosensors in Consumer Electronics

Biosensors are electrochemical devices that determine the composition of biological fluids. A blood glucose meter is a good example of biosensors and indeed is virtually the only example of a biosensor device currently available on the mass market. 

However, many people are hopeful that advances in biosensor technology like those made by the research team at MIPT could pave the way for more consumer electronics that include them. Examples of consumer electronics could include smartphones, wearable health and exercise sensors, and household appliances that could analyse bodily fluids for applications such as identity verification, medical analysis, and diet planning. 

According to Valentyn Volkov, head of the MIPT Center for Photonics and 2D Materials, the team’s development will take biosensors to a “qualitatively new level”. However, it is estimated that it will take two-to-three years to develop an industrial design based on the proposed technology.