Rapid monitoring of benzylpenicillin sodium using Raman and surface enhanced Raman spectroscopy

•The Ag NPs assembly was served as SERS substrate for detecting the penicillin drug.•NaBP is close to Ag surface by carboxyl. The detection limit arrives at 10−7 mol/L.•A quantitative detection of NaBP can be performed in the range of 10−4–10−7 mol/L.•The stability of NaBP in acid and alkali conditions can be monitored by using SERS.

At present, fluorescence spectroscopy, ultraviolet spectroscopy and infrared spectroscopy are usually used to detect drug molecules, however the information about using Raman spectroscopy to detect drug molecules is very few. In this work normal Raman spectroscopy and surface-enhanced Raman spectroscopy were utilized to study benzylpenicillin sodium (NaBP). The results show that NaBP is close to the surface of silver substrate through the carboxyl group, and the detection limit of NaBP is reduced to 1 × 10−7 mol/L. Accordingly, the quantitative analysis of NaBP can be carried out in the range of 1 × 10−4–1 × 10−7 mol/L concentration. And it is proved that NaBP is not stable in acid and alkali conditions and the decomposition reaction is very complex.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide