Carbon nanotube based electrical immunosensor to rapidly detect troponin I during a heart attack

Heart disease is the leading cause of death for both men and women. Therefore, a fast and reliable diagnosis of heart attack is urgently needed. A study, led by Prof. Jaesung Jang (School of Mechanical and Nuclear Engineering) has developed an electrical immunosensor to detect the acute myocardial infarction, also known as a heart attack within a minute. The system works by measuring the level of cardiac troponin I (cTnI), a protein that is excreted by the heart muscle into the blood following a heart attack.

Image shown above is the core material used for the new immunosensor that detects proteins in the blood stream following a heart attack, providing results in just 1 minute. Credit: Uslan National Institute of Science and Technology

Prof. Jang states, “This new immunosensor is constructed in a different way than any other sensor.” He adds, “Owing to the new design of this immunosensor, this device is able to rapidly diagnose the level of heart attacks at the point of care.”

Using just a single droplet of blood, this immunosensor detects the target protein present in the blood serum following a heart attack and provides a result in 1 minute.

In the study, dielectrophoretic (DEP) forces have been applied to attract the target protein. The incubation time required for the detection is decreased through DEP-mediated biomarker concentration, in which the target protein is attracted to the sensing areas via electrical forces. Therefore, the dielectrophoretic concentration of cTnI reduced the incubation time required from 60 min to 1 min.

Chang-Ho Han (School of Mechanical and Nuclear Engineering), a combined masters doctoral student in Prof. Jang’s group notes, “The level of cTnI within a single droplet of blood serum is not great.” He continues, “However, we were able to attract the target protein onto the sensing areas via electrical forces, thereby greatly improving detection time and detection limit.”

According to the research team, this novel immunosensor holds considerable potential for use as a platform for sensing distinct types of proteins, along with the feasibility of miniaturization and integration for biomedical diagnosis.

The findings of the research have been published in biotechnology journal Biosensors & Bioelectronics.

Citation: Sharma, Abhinav, Chang-Ho Han, and Jaesung Jang. “Rapid electrical immunoassay of the cardiac biomarker troponin I through dielectrophoretic concentration using imbedded electrodes.” Biosensors and Bioelectronics 82 (2016): 78-84.
DOI: 10.1016/j.bios.2016.03.056
Research funding: National Research Foundation of Korea, Korean Ministry of Education, 2016 Research Fund of UNIST.
Adapted from press release by Uslan National Institute of Science and Technology.