“Pathogenic E. coli can be detected in 5 minutes”… Development of real-time detection technology for infectious pathogens

[IT비즈뉴스 최태우 기자] A technology was developed that monitors the gene amplification process in real time and detects the amplification of a single copy of the pathogenic E. coli in the sample in 5 minutes by detecting minute electrical signal changes caused by the amplified gene.

The Korea Research Foundation announced on the 9th that the research team of the Bio-Nano Health Guard Research Group has developed a highly sensitive pathogen detection technology based on real-time monitoring of the nucleic acid amplification reaction of pathogens.

In the case of commercialized gene amplification equipment for diagnosis of pathogens, there is a difficulty in on-site diagnosis due to the limitation of miniaturization of fluorescence detection equipment. In addition, there is a limitation in simultaneously detecting several components in one sample due to the wavelength overlapping of the fluorescent labeling material.

Accordingly, there is active development of technology using an impedance sensor that captures changes in electrical signals that appear when charged nucleic acids are amplified without a separate label.

However, by minimizing the electric polarization caused by various materials carrying charges in the amplification reaction solution, it is necessary to increase the sensitivity of the sensor to properly capture the change in the signal caused by the amplified external gene.

The research team focused on improving the sensitivity of electrical impedance sensors using nanogap sensors.

The nanogap sensor can effectively reduce the signal loss due to electric potential drop by reducing electrode polarization, thereby increasing the sensitivity of measuring minute electrical signal changes in the sample by 50%.

With this nanogap impedance sensor-based isothermal gene amplification, it succeeded in detecting the amplification of a single copy of the target DNA of E. coli O157:H7 in 5 minutes. A sample in which a single cell of E. coli was present was also detected.

In particular, it is expected to contribute to the development of equipment to facilitate on-site detection of pathogens as it can read signal changes at isothermal temperatures without complicated temperature control or equipment for fluorescence capture while using existing commercially available gene amplification reagents.

The research results, supported by the Global Frontier Project promoted by the Ministry of Science and ICT and the Korea Research Foundation, were published in the journal’Biosensors and Bioelectronics’.