Researchers at JILA, operated jointly by the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, are utilizing laser “frequency combs” to help researchers evaluate a novel instrument that kills harmful bacteria without the use of liquid chemicals or high temperatures.
The decontamination instrument delivers an air stream of free radicals—highly reactive molecules—to quickly kill bacteria. The system delivers the air stream up to three meters away and has demonstrated high-level disinfection of Staphylococcus aureus and Pseudomonas aeruginosa. Such pathogens are of concern in medical settings for causing pneumonia and other diseases. The method also proved effective against difficult-to-eradicate spores of Bacillus atrophaes and biofilms of Escherichia coli.
The frequency combs are generated by ultrafast lasers, which precisely measure individual frequencies of light. The research team is using such a comb to identify specific molecules in gases based on which colors of light, or comb “teeth,” are absorbed by the gas, and in what amounts.
Mark Golkowski, Assistant Professor of Electrical Engineering and Bioengineering at the University of Colorado Denver, said JILA’s comb measurements help explain for the first time how his decontamination technique inactivates bacteria, and therefore will “help optimize solutions for the medical clinic where multi-drug resistant bacteria are a growing problem.”
“JILA provided us the unique capability of an extremely sensitive measurement and one that also yields information about the interaction dynamics, since many molecules can be simultaneously observed on short time scales,” Golkowski said.
The comb technique captures the complex chemical reactions in the sterilization system in real time. “The multiple and simultaneous reactions make numerical modeling of the chemical dynamics difficult, hence the need for direct measurement of simultaneous concentrations, a capability that the frequency comb spectroscopy uniquely provides.”
The JILA measurements are funded by NIST and the Air Force Office of Scientific Research (AFOSR). Learn more about JILA at http://jila.colorado.edu/.