Surface-enhanced Raman scattering of graphene oxide chemically modified by perylene diimide

A soluble perylene diimide derivative are bonded to graphene oxide via esterification, which is applied as the flexible surface-enhanced Raman scattering active substrate for detecting rhodamine 6G. The esterification destroys the crystalline structure of graphene oxide and causes graphitization to some extent. The efficient charge transfer processes from rhodamine 6G and perylene diimide to graphene oxide result in the weak emissions and reduce the background signals. The enhanced Raman signals of rhodamine 6 G on graphene oxide-perylene diimide is increased nearly four times that on graphene oxide without modification. The analysis of the optical spectra and energy levels of the compounds indicates that the multiple charge transfer processes contribute to the enhanced Raman signals of rhodamine 6G on graphene oxide-perylene diimide.