Ultrasensitive sensor detects hepatitis B
doi:10.1038/nindia.2018.145 Published online 16 November 2018
Researchers have invented a sensor chip that can detect ultra-low concentrations of a toxin secreted by the hepatitis B virus, making it potentially useful for detecting the virus at an early stage of infection1.
The hepatitis B virus wreaks havoc on the liver. Long-term infection caused by this virus kills liver cells, eventually leading to liver cancer and cirrhosis. Globally, this virus chronically infects millions every year, stressing the need for a fast and sensitive sensor.
In their search of such an ultrasensitive sensor, scientists from the Indian Institute of Engineering Science and Technology in West Bengal, India, have designed a sensor chip using vertically arrayed zinc oxide nanorods and specific electrodes. They then attached an antibody specific to the hepatitis B virus toxin to the sensor.
When exposed to different test solutions containing the bacterial toxin, the antibody on the sensor bound to the toxin. This binding caused a change in the electrical conductivity and voltage of the sensor, signalling the presence of the viral toxin.
The sensor was able to detect the presence of the hepatitis B virus in blood samples even when the viral toxin is present at a concentration of a billionth of a billionth of a mole.
The sensor will help in initiating early medical treatment, reducing the treatment cost and mortality due to infections caused by the hepatitis B virus. The researchers add that this sensor could also be used for the detection of protein biomarkers of various diseases, including several types of cancers.
1. Chakraborty, B. et al. Liquid gated ZnO nanorod FET sensor for ultrasensitive detection of Hepatitis B surface antigen with vertical electrode configuration. Biosens. Bioelectron. 122, 58-67 (2018).