SERS study of different configurations of pharmaceutical and natural product molecules ginsenoside Rg3 under the interaction with human serum albumin on simple self-assembled substrate

SERS spectra of both 20(R) and 20(S)-ginsenoside Rg3 were used to predict similar orientation geometry for the alkyl chain portion with a minor difference in the carbocyclic rings. When combined with HSA, the flexible portion of alkyl chains assumes a collectively similar transformation on the Ag surface with the glucose rings perpendicularly plugging into the hydrophobic site of HSA.