Fast and sensitive detection of Procainamide: Combined SERS and DFT modeling studies

Abstract

In this study, a surface-enhanced Raman scattering (SERS) spectroscopic approach was developed for a trace-level detection of procainamide in an aqueous medium. Silver-based nanoparticles as active substrates were synthesized using the reduction technique in presence of a citrate stabilizer and were characterized with UV–Vis, FT-IR, and FE-SEM techniques. The SERS spectra of procainamide were collected at a wide concentration range. The vibrational bands and frequency shifts associated with the enhanced Raman signals were identified, analyzed, and assigned to respective active modes. First-principle calculations were performed to elaborate on potential substrate-drug interaction possibilities and energies at the molecular level. The intensity enhancements observed for selected SERS peaks, namely at 1246 cm−1, 1370 cm−1, 1613 cm−1 and 1661 cm−1, were further utilized for the development of a consistent and fast quantification of procainamide. The developed approach displayed an excellent sensitivity and good reproducibility. The detection limit for procainamide was successfully attained at the level of one-tenth of nanomolar concentrations corresponding to a coefficient of regression (R2) of 0.9998. The obtained results revealed that this method is promising for drug and medical applications.