Sometimes it's hard to tell if you have bad breath, and asking someone to check if it's fresh can be embarrassing. But thanks to science, there may soon be an easier way to find out. Researchers are now working on a sensor to detect hydrogen sulfide, the gas that makes breath stink. Bad breath can happen sometimes, or it can be a chronic condition known as halitosis. It can be caused by foods, poor oral hygiene, diseases, or other things. The issue has inspired a set of complex experiments designed to detect the odor-causing gas without using the human sense of smell. Now, researchers have developed a small sensor that can do just that. The team -- led by Il-Doo Kim, PhD, from the Advanced Institute of Science and Technology in South Korea -- subjected a solution of metal salt, sodium chloride, platinum metal nanoparticles, and tungsten, a rare metal, to a manufacturing technique called electrospinning, producing tiny fibers. Previous studies have shown that when metal oxides react with sulfur-containing gases, they have electrical changes that can be measured. So, the researchers heated their nanofibers, causing the tungsten to oxidize. The nanofibers had the biggest reaction to hydrogen sulfide when their solution contained equal amounts of platinum and tungsten. The researchers tested a couple of other sulfur-containing gases, such as dimethyl sulfide and methyl mercaptan, but their fibers were most susceptible to hydrogen sulfide. A Tiny Prototype A prototype to detect bad breath combines nanofiber-coated gold electrodes with sensors that detect gas, humidity, temperature, and pressure. It correctly identifies bad breath from exhaled air, without any special collection or filtering equipment, 86% of the time. A small device could be produced for a quick and easy self-diagnosis of bad breath, the researchers say. Until then, the best way to prevent foul-smelling breath is to avoid culprit foods and tobacco, and to brush and floss often. Scrape your tongue, rinse your mouth, and consider chewing sugarless gum to keep the mouth moist and fresh. Source
