Sensor detects bacteria that cause stomach cancer
doi:10.1038/nindia.2018.122 Published online 23 September 2018
Researchers have designed a sensitive sensor that can detect minute traces of Helicobacter pylori, a bacterium that infects the inner lining of the stomach1. Since this bacterium is known to cause stomach cancer, this sensor will be useful for making early diagnosis of the disease.
Besides cancer, long-term infection with H. pylori also triggers ulcers in the upper part of the small intestine and in the stomach. Current techniques for detecting this bacterium are expensive, inefficient and time-consuming.
Scientists, led by Utkarsh Jain, from Amity University in Noida, Uttar Pradesh, and Kiel University in Kiel, Germany, have created an efficient sensor by irradiating a hybrid material made by coating a screen-printed electrode with nanosized zinc oxide tetrapods. They then attached an antigen, a bacterial toxin isolated from H. pylori, to the surface of the sensor.
In response to H. pylori infection, humans secrete specific antibodies, a class of proteins that eliminate infection by binding to the H. pylori-specific antigen.
When the sensor was exposed to different concentrations of such antibodies, peak current decreased with increasing concentration of the antibodies. The sensor maintained its sensitivity up to 30 degrees Celsius and selectively detected the bacterial antigen even in the presence of other interfering agents.
It retained 90% of its original sensitivity when stored at 4 degrees C for two months. Since this sensor is extremely sensitive and stable, it could potentially be used to diagnose H. pylori infection in a clinical set-up, says Jain.
1. Chauhan, N. et al. Zinc oxide tetrapods based biohybrid interface for voltammetric sensing of Helicobacter pylori. ACS Appl. Mater. Interfaces.(2018) doi: 10.1021/acsami.8b08901