Keeping wounds covered can help them stay clean. But if bacteria grow beneath the bandages, things can get dangerous.
LIFE, AT ALL scales, leaves behind chemical fingerprints. Some are scents we can pick up with our noses: Jasmine petals lend their sweet aldehydes; an upstairs neighbor leaves his noxious amines in the stairwell. “But there are also gasses that we can’t smell, because they’re just that basic kind of background,” says Andrew Mills, a professor of chemistry at Queen’s University Belfast, United Kingdom. “Things basically undergoing life, turning oxygen into carbon dioxide.”
Mills specializes in detecting volatile chemicals, from stinky sulfides to odorless CO2. His lab has focused on sensing gasses as signatures of strange life in undesirable places: Think contaminated ground beef and—more recently—infected wounds. In a study published last month in the journal Chemical Communications, Mills unveiled a simple CO2 detector that can be inserted into dressings for chronic wounds. It changes color when it senses rising concentrations of the gas, a tell-tale sign of dangerous infections.