Surfactant‐aided surface enhanced Raman scattering of Ni(II) tetrasulphonate phthalocyanine in silver sol

Surface enhanced Raman scattering (SERS) has been used to investigate the structure, surface reaction and enhancement mechanism of adsorbed molecules on metal surfaces. However, a major limitation has been having to choose the molecules with functional groups capable of adsorbing onto metal surfaces. We report here SERS of Ni(II) tetrasulphonate phthalocyanine (Ni(II)PCS) as a result of introducing cationic surfactants like CTAB or CTAC. Ni(II)PCS does not adsorb onto a silver surface by itself and consequently does not show any SERS effect. The cationic surfactants employed here have functional groups to adsorb onto a silver surface and simultaneously interact with anionic sulphonate groups of Ni(II)PCS. Surfactant‐aided SERS would expand the range of SERS application to molecules which are not able to adsorb onto metal surfaces by themselves.