Researchers at the Korea Institute of Science and Technology (KIST) have succeeded in developing a biosensor source technology that improves sensitivity by increasing the sensitivity of field-effect transistors (FET) using electrical signals.

Despite FET-based molecular detection technology’s detection of various molecules such as viruses, proteins, and DNA, it has not been easy to commercialize the technology because the detectable molecular region becomes thinner as the concentration of ions and electric charges present in the solution of the detector increases, according to the institute.

Researchers have tried to increase the molecular detection ability through various strategies, such as diluting the test solution, such as blood, up to 100,000 times.

However, there have not been any positive results so far.

To resolve the problem, the team used human cell membranes.

“The cell membrane of the human body not only regulates the concentration of ions inside and outside the cell but also inhibits the penetration of high-concentration ions into the cell,” the institute said. "Therefore, the researchers paid attention to these properties of the cell membrane."

After repeated experiments of applying a cell membrane to the existing FET-based molecular detection chip surface, the team confirmed that molecular detection is possible even in a high-concentration ion solution without additional pretreatment.

The new technology, called "Lipid-FET," can detect desired molecules more sensitively than existing sensors without diluting the test solution more than 100,000 times as in the past and using the bloodstock solution as it is.

"The technology showed the best performance among the field-effect-based molecular detection technologies reported worldwide so far," the institute said.

What is more noteworthy about this research result is that the technology is a platform technology that can diagnose various diseases, such as dementia protein, and is applicable for biosensors used in the medical, health, and environmental fields, it added.

Doctors Yoo Yong-sang of the Brain Science Research Center and Kim Chul-ki of the Sensor System Research Center at KIST led the study. Professor Ahn Dong-joon of the Department of Chemical Engineering and Biotechnology at Korea University also participated in the study.

"The cell membrane-FET molecular detection technology, developed through convergence research by joint researchers in various fields, is a technology that researchers can directly apply to any system that detects molecules using current electrical signals," Doctor Yoo said.

Doctor Kim also said, "We are conducting research to apply the technology to various research fields, such as a technology to more rapidly and precisely diagnose not only diseases such as dementia, Parkinson's disease, and diabetes, known to cause protein denaturation by adsorption to cell membranes, and detecting very small amounts of infectious viruses such as Covid-19."

Nature Communications has published the result of the study.