Researchers at Singapore’s Nanyang Technological University (NTU) have developed a device that can detect a wide spectrum of airborne chemical compounds instantly. The development could lead to better chemical monitoring in the ambient environment as well as in facilities where volatile and dangerous chemicals are present.
Currently, gaseous chemicals are monitored through a process called gas chromatography-mass spectrometry (GC-MS). While GC-MS is capable of detecting even trace amounts of a chemical in a sample, the technique requires several hours, if not several days, to produce accurate results. In emergency situations such as natural disasters, chemical spills or illegal dumping of toxic waste, however, fast and ongoing analysis of potential air contamination is essential to enabling emergency responders to act appropriately.
In an effort toshorten the time to result, NTU engineers have built a new device that uses a porous, metallic nanomaterial to trap gas molecules within its voids. Once trapped, these gases are exposed to a laser beam, and the coherent light passing through them dips into a lower energy state that can be translated into a spectroscopic graph that acts like a “chemical fingerprint”. With that graph in hand, researchers can immediately detect what chemicals are present in the gas sample.
According to NTU, the entire process for examining the constituent parts of a gas sample takes a mere 10 seconds.
In experiments, NTU researchers were able to detect a variety of hazardous chemicals, including polyaromatic hydrocarbons (PAH), including naphthalene and derivatives of benzene, all of which are difficult to detect and highly carcinogenic.
“Our device can work remotely, so the operation of the laser camera and analysis of chemicals can be done safely at a distance. This is especially useful when it is not known if the gases are hazardous to human health,” explained Associate Professor LingXing Yi, who heads the Division of Chemistry & Biological Chemistry at NTU.
If refined further, the NTU detector could make industrial facilities much safer for workers. Furthermore, ambient environments, particularly those in urban settings, could be better monitored for air pollution concentrations, and even war zones could be made safer if chemical weapons use could be detected immediately.