AsianScientist (Jan. 6, 2020) – Scientists at Nanyang Technological University (NTU), Singapore, have developed a device for rapidly identifying a wide range of airborne gases and chemicals. They published their findings in ACS Nano.
When gas or chemical leaks occur, the ability to identify the airborne contaminant is key to determining the appropriate response. However, identifying gaseous hazards typically involve the use a laboratory technique called gas chromatography-mass spectrometry, which is reliable but requires tedious sample collection. It may be a few hours or days to obtain results from air samples.
In the present study, researchers at NTU led by Associate Professor Ling Xing Yi developed a portable prototype device that allows for real-time monitoring of air quality and detects gas leaks and industrial air pollution.
A key component of the device is a small patch made of a special porous and metallic nanomaterial to first trap gas molecules. When a laser is shone on the patch from a few meters away, the light interacts with the gas molecules, causing light of a lower energy to be emitted. The metal nanoparticles embedded in the patch also boost the intensity of the emitted light.
Analysis of the emitted light results in a readout that acts like a ‘fingerprint’ corresponding to various chemicals present on the patch. The whole process takes about ten seconds to complete. These chemical fingerprints are then referenced against a digital library of fingerprints to quickly determine what chemicals have been detected.
“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,” Ling explained.
The team showed that the device can identify airborne molecules such as polyaromatic hydrocarbons (PAH), including naphthalene and derivatives of benzene, a family of colorless industrial air pollutants known to be highly carcinogenic.
It can detect PAHs at parts-per-billion concentrations in the atmosphere as well as perform continuous monitoring of the concentration of different types of gases like carbon dioxide in the atmosphere, which could be a useful application in many industrial settings. The laser used in the device is also of a lower intensity, making the system safe to operate and more energy efficient.
The team has filed for a patent and is now commercializing the technology for use in pollution monitoring, chemical disaster response, as well as other industrial applications.
The article can be found at: Phan-Quang et al. (2019) Tracking Airborne Molecules from Afar: Three-Dimensional Metal–Organic Framework-Surface-Enhanced Raman Scattering Platform for Stand-Off and Real-Time Atmospheric Monitoring.
Source: Nanyang Technological University.
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