Introduction
The Raman effect is a phenomenon in molecular spectroscopy where light scattered from a molecule or crystal undergoes a shift in frequency. It was discovered by Indian physicist Sir C. V. Raman in 1928, for which he won the Nobel Prize in Physics in 1930. The Raman effect has since become an important tool for analyzing chemical compounds and materials.
How does it work?
When light interacts with a molecule, most of it is scattered with the same frequency as the incident light (Rayleigh scattering). However, a small fraction of the light undergoes a frequency shift, either to higher energy (Stokes scattering) or lower energy (Anti-Stokes scattering). This shift in frequency is due to the molecules’ vibrations and rotations, providing valuable information about their structure and composition.
Examples
- Identifying unknown substances: Raman spectroscopy is used in forensics to analyze trace evidence, in pharmaceuticals to verify drug compositions, and in archaeology to study ancient artifacts.
- Studying biological processes: Raman imaging can map the distribution of molecules in living cells, providing insights into cellular functions and diseases.
- Monitoring environmental pollutants: Raman spectroscopy can detect and quantify pollutants in air, water, and soil, aiding in environmental monitoring and remediation.
Case Studies
A pharmaceutical company used Raman spectroscopy to identify counterfeit drugs in the market, saving millions in potential losses and protecting public health. A research team used Raman imaging to study the degradation of plastics in marine environments, leading to new eco-friendly materials design.
Statistics
According to a market research report, the global Raman spectroscopy market is projected to reach $300 million by 2025, driven by increasing applications in pharmaceuticals, materials science, and environmental monitoring.
