Demonstration of Physical and Analytical Features of Surface-Enhanced Raman Scattering by Analysis of Folic Acid in Commercial Tablets

A novel two-part laboratory demonstration of surface-enhanced Raman scattering (SERS) spectroscopy was successfully implemented for undergraduate and graduate students in physical and analytical chemistry. The first part enables students to understand how the choice of the excitation laser line affects the SERS spectra. It is clearly demonstrated that intense SERS spectra arise only when the wavelength of the excitation line falls into the region of electromagnetic resonance, while the enhancement is negligible under off-resonance conditions. The second part illustrates to the students the analytical benefits of SERS spectroscopy through fast and simple identification of folic acid in a commercial tablet. The presented demonstration is designed to allow students to use silver nanoparticles that they obtained in other related laboratory experiments. Using a well-known drug also stirs up the student’s interest and was applied to teaching the SERS method for the first time. Importantly, the demonstration allows students to understand some fundamentals of SERS spectroscopy and at the same time to recognize its practical potential for high-throughput analysis.