Sensor detecting biomarker for cancer, Alzheimer’s disease
doi:10.1038/nindia.2018.141 Published online 10 November 2018
Researchers have invented a sensitive sensor that can detect trace amounts of hydrogen peroxide in normal as well as diseased cells1. Since diseased cells make more hydrogen peroxide than normal cells, this sensor could be useful for distinguishing healthy cells from diseased cells in cancers and Alzheimer’s disease.
Hydrogen peroxide is an oxidising agent and a common by-product of a specific enzyme activity in living cells. It plays vital roles in biological signalling processes. However, when its concentration goes up, it triggers inflammation, leading to disorders such as cancer, heart disease and Alzheimer’s.
To devise a sensor that can measure the concentration of hydrogen peroxide in living cells, scientists from the Banaras Hindu University in Varanasi, India, prepared a nanocomposite using palladium nanoparticles and microspheres of silicon dioxide. They then converted the nanocomposite into a sensor.
When exposed to a specific solution containing hydrogen peroxide, the sensor displayed a current response. Increasing the concentration of hydrogen peroxide in the solution increased the current response of the sensor. The sensor didn’t show any current response when exposed to a solution devoid of hydrogen peroxide.
The sensor could detect hydrogen peroxide even in the presence of interfering agents such as ascorbic acid, uric acid, glucose, adenine, thymine and guanine, all of which are usually found in living cells. It detected hydrogen peroxide in less than two seconds.
Besides being non-toxic to cervical cancer cells and normal human skin cells, the sensor efficiently sensed hydrogen peroxide in these living cells.
1. Gupta, R. et al. Palladium nanoparticles supported on mesoporous silica microspheres for enzyme-free amperometric detection of H2O2 released from living cells. Sensor. Actuator. B. Chem. 276, 517-525 (2018)