IIT-B: Sniffing out lung cancer, explosives

Why it is in news?
  • Clinical applications for early-stage detection will become possible once validated on humans - Researchers at the Indian Institute of Technology (IIT) Bombay have set the stage to possibly sniff out in about a minute early-stage lung cancer from exhaled breath.
More in news
  • A two-member team has developed a platform that detects volatile organic compounds such as benzene, acetone, benzaldehyde and ethanol in a gas phase at single molecular levels.
  • These organic compounds in exhaled breath are clinically established biomarkers for early stage lung cancer. The same platform can also be used to monitor air-pollution levels or detect explosives like TNT (trinitrotoluene).
  • The volatile compounds have been detected using lab samples and clinical applications for detecting early-stage lung cancer will become possible once validated on human subjects.
  • Raman scattering- Since Raman scattering is an inherently weak phenomenon, the researchers turned to surface-enhanced Raman scattering to dramatically increase the sensitivity of the platform such that it detects molecules at extremely low concentrations using a small amount of sample.
  • When liquid containing the nanoparticles is subjected to a thermal gradient (one end is kept hot while the other is cold) the nanoparticles tend to migrate from the hot end to the cold one.
  • As a result, the concentration of nanoparticles at the cold end increases. When the concentration of nanoparticles at the cold end increases they self-assemble to form the cage.
  • The cage then traps the molecule, whether it is in a liquid or gas state.
  • Once the molecule gets trapped, the Raman spectrum gets enhanced as the cage is made of nanoparticles.
  • Since testing the technique on human subjects for early-stage lung cancer detection is riddled with ethical and clinical challenges, the researchers looked at low-hanging fruit.
  • This platform is particularly suited for the detection of plastic explosives such as TNT and RDX.
  • To detect the presence of explosives, air sample containing the molecules is forced into water that contains nanoparticle cages; the molecules get trapped in the cages.
  • The presence of molecules is detected by shining laser and measuring the Raman spectrum. The entire process of sample collection and signal acquisitions takes about 2-3 minutes.
Source
The Hindu




Posted by Jawwad Kazi on 16th Sep 2018