In situ surface enhanced Raman scattering (SERS) in solution was tested in this study at ambient temperature and high pressure (up to 978 MPa) in a diamond-anvil cell, with the intent of resolving trace detection in high pressure conditions. The 4-chlorothiophenol solution was used as the analyte in our experiments. A silver nanoparticle layer, formed by chemical reduction and assembled on a poly (allylamine hydrochloride)-modified silicon wafer, was used as the substrate. There was an obvious rise in SERS intensity when the sample chamber was pressurized for the first time in the diamond-anvil cell. But then the intensity drop occurred with increasing pressure and all peaks have pressure-induced blue shift below 700 MPa. The SERS intensity and Raman shift displayed irregular changes in the pressure range from 700 MPa to 978 MPa. The discovery of the survival of in situ high-pressure SERS in solution in the present study may make it a prospecting tool for the high-precision detection of analyte in high pressure conditions. Moreover, it could provide more information on the SERS mechanisms that have been puzzling us for decades. 

In situ surface enhanced Raman scattering (SERS) in solution was tested in this study at ambient temperature and high pressure (up to 978 MPa) in a diamond-anvil cell, with the intent of resolving trace detection in high pressure conditions. The 4-chlorothiophenol solution was used as the analyte in our experiments. A silver nanoparticle layer, formed by chemical reduction and assembled on a poly (allylamine hydrochloride)-modified silicon wafer, was used as the substrate. There was an obvious rise in SERS intensity when the sample chamber was pressurized for the first time in the diamond-anvil cell. But then the intensity drop occurred with increasing pressure and all peaks have pressure-induced blue shift below 700 MPa. The SERS intensity and Raman shift displayed irregular changes in the pressure range from 700 MPa to 978 MPa. The discovery of the survival of in situ high-pressure SERS in solution in the present study may make it a prospecting tool for the high-precision detection of analyte in high pressure conditions. Moreover, it could provide more information on the SERS mechanisms that have been puzzling us for decades.