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Spring 2021

New approach to airborne disinfection uses food-coloring dyes

by Chris Adam

Detection and Diagnosis

This image shows a new approach to airborne disinfection using food-coloring dyes.
Image provided

Young Kim, Associate Professor of Biomedical Engineering
Purdue University photo/Rebecca McElhoe

The COVID-19 pandemic has shed new light on the needs for improved disinfection methods, both for individuals and facilities.

Purdue researchers have developed an airborne disinfection method — using food-coloring dyes — to be applied to the entire body and rooms for sterilization purposes and lowering the risk of infection. The team’s disinfection method uses edible materials. “Most of the antiviral and antibacterial sprays used for airborne antiviral and antibacterial disinfectants, such as aerosolized hydrogen peroxide, ozone and deep ultraviolet illumination, are a biohazard risk to humans,” says Young Kim, associate professor of biomedical engineering. “Additionally, disinfectants containing titanium dioxide and noble metal nanoparticles pose carcinogenic and cytotoxicity risks.”

Kim also says new methods are needed since transmission of pathogens (viruses and bacteria) often occurs in the air and infection with pathogens is transmitted by an airborne route. The Purdue method might also help in medical settings, where healthcare workers typically are exposed to the disease-causing agents when they take off their personal protective equipment.

The Purdue airborne antiviral phototherapy technique uses small aerosols of FDA-approved food coloring dyes to mitigate the risks of airborne transmissions of pathogens. This is referred to as Photodynamic Airborne Cleaner (PAC).

“We have demonstrated with our novel solution how visible light activation of several FDA-approved food coloring dyes generates singlet oxygen, which can be used to kill airborne pathogens,” Kim says. “In the medical community, it is well known that singlet oxygen is effective to inactivate viruses. We are developing a scalable aerosol generation system for the dyes, allowing uniform fog-like dispersion lingering in the air to minimize wetting and surface staining. This technology can be installed in a confined chamber for healthcare professionals to change PPE in hospital settings.”

The novel photoreactive arrangement can be used in rooms where many people are present at risk of airborne pathogen exposure.


The researchers are looking for partners to continue developing their technology.

For more information on licensing and other opportunities, contact D.H.R. Sarma of OTC at DHRSarma@prf.org and mention track code: