Chinmaya IAS Academy – Current Affairs Chinmaya IAS Academy – Current Affairs
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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. A two-member team led by Chandramouli Subramaniam from the institute’s Department of Chemistry 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. The results were published in the journal ACS Sustainable Chemistry and Engineering. 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. “In our studies, we were able to reliably achieve sensitivities to the level of tens of molecules,” he says. “We put the molecule of interest on a gold or silver nanoparticle and then record the Raman spectrum. When we shine light [laser] on the sample [molecule plus the nanoparticle], the Raman spectrum of the molecule gets enhanced,” says Prof. Subramaniam. “The intensity enhancement of Raman spectrum happens predominantly through the interaction of localised electromagnetic field on the nanoparticles surface with the vibrational modes of the molecule.”
