Hydrogen: IISc Develops Paper Disks to Detect Hydrogen Peroxide, a Chemical with a Wide Range of Uses From Disinfectants to Rockets | India News

BENGALURU: In a new discovery that promises to be used in various fields, researchers at the Indian Institute of Science (IISc) have developed a paper-based sensor to detect even tiny volumes of hydrogen peroxide.
Hydrogen peroxide is a chemical widely used in household and healthcare products like hand sanitizer as a disinfectant, in rocket fuel as a propellant, and is also found in biological cells, the IISc said in a statement.
The technique used by the researchers consisted of preparing a gel from a solution containing a specially designed molecule, treated with a liquid containing hydrogen peroxide and air-drying them on a thin paper disk of about 0.45cm in diameter. The paper disc emits green light when placed under a UV lamp, only in the presence of hydrogen peroxide. The intensity of light was found to be directly proportional to the concentration of hydrogen peroxide.

Diagram illustrating the hydrogen peroxide detection process | Credit: IISc

“…You can actually visualize this green emission (photoluminescence) with the naked eye and you don’t need fancy instruments. All you need is a simple source of UV light,” explained Arnab Dutta, a PhD student in the Department of Organic Chemistry at IISc and first author of the study published in ACS Sensors.
The statement adds that because the paper disc is inexpensive, biodegradable and easy to use, it could serve as a powerful tool in low-resource settings, even for testing biological fluids like blood.
“Effective detection of hydrogen peroxide is also crucial in other areas: peroxide-based explosives, for example, can be traced using hydrogen peroxide which is sometimes used as a raw material. When the researchers used their technique to randomly test five different brands of hand sanitizer, they found only three containing the level of hydrogen peroxide mandated by the World Health Organization (WHO) – 0.125 %. The fourth seemed to have much less than 0.125% and the fifth had almost zero hydrogen peroxide,” IISc said.
Professor Uday Maitra from the Department of Organic Chemistry and lead author of the study said hydrogen peroxide can be detected on a larger scale using titration and other experiments, but these are cumbersome and require careful analysis. training.
“…This method is easy because of its simplicity,” said Maitra, whose lab has worked on the development of several “sensitizing” molecules that activate the photoluminescence of elements called lanthanides in the presence of chemicals or compounds. specific.
His lab has already developed paper-based sensors to detect specific antioxidants in green tea – and thus test its quality – as well as sensors for various enzymes.
IISc added that the sensitizing molecule they designed in this study allows a metal called terbium to emit green light under a UV lamp. When the sensitizer is combined with a masking agent, the green light disappears, and when hydrogen peroxide is added to this combination, it unmasks the sensitizer molecule, causing it to glow green again.
“The way we designed the mask, that’s where the thinking process comes in…The molecule we designed is very specifically unmasked by hydrogen peroxide,” Maitra explains.
His team is currently working to reduce reaction time; it takes a bit longer if the concentration of hydrogen peroxide is lower, IISc said, while Maitra added that they are also working on developing a small, portable device where detection can be done in a way more automated.
“We are in contact with a start-up in Chennai. We have some prototypes made with UV LEDs and a camera, to generate the emission, take a photo and use an image processing application to quantify the amount of hydrogen peroxide,” he said.