A new method for rapid identification of traditional Chinese medicine based on a new silver sol: using the SERS spectrum for quality control of flavonoids and flavonoid glycosides in Potentilla discolor Bge.

Rapid identification of the structure and active components of traditional Chinese medicine is still limited due to low extraction efficiency, long time requirements and imprecision. To overcome these limitations, we developed a novel surface-enhanced Raman spectroscopy (SERS) base, Ag@Cs nanoparticles, which enhanced the effectiveness of Raman spectroscopy and enabled trace analysis of drugs. Cesium ions have remarkable chemical activity and photoelectric effects. Here, the novel approach involved using cesium ions as focusing agents and thiosulfate ions as cleaning agents. Its distinctive feature lies in the introduction of cesium ions as focusing agents, which facilitates the surface modification of silver nanoparticles, leading to the formation of hotspots and consequently achieving highly repetitive and high signal-to-noise ratio Raman spectra. The results demonstrated that Ag@Cs, compared with the original method, greatly enhanced the spectral signal magnitude of glycogens and glycosides in twenty kinds of Potentilla discolor Bge. Additionally, Ag@Cs SERS enabled the analysis of glycogens and glycosides in twenty samples, which showed obvious and different corresponding characteristic peaks to distinguish them. Furthermore, by analyzing the peak spectrum information and principal component analysis of glycogen and glycoside components from ten different origins, the quality of the different origins can be determined. Compared with the original method, it was proved that Ag@Cs base could overcome the influence of citrate ions and was effectively applied in the SERS detection of flavonoids containing fluorescent components. Therefore, this method has potential applications in Chinese medicine quality control and testing technology.