Surface Enhanced Raman Spectroscopy of Organic Molecules on Magnetite (Fe3O4) Nanoparticles.
Surface-enhanced Raman spectroscopy (SERS) of species bound to environmentally relevant oxide nanoparticles is largely limited to organic molecules structurally related to catechol that facilitate a chemical enhancement of the Raman signal. Here, we report that magnetite (Fe3O4) nanoparticles provide a SERS signal from oxalic acid and cysteine via an electric field enhancement. Magnetite thus likely provides an oxide substrate for SERS study of any adsorbed organic molecule. This substrate combines benefits from both metal-based and chemical SERS by providing an oxide surface for studies of environmentally and catalytically relevant detailed chemical bonding information with fewer restrictions of molecular structure or binding mechanisms. Therefore, the magnetite-based SERS demonstrated here provides a new approach to establishing the surface interactions of environmentally relevant organic ligands and mineral surfaces.
†Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Namhey
N
Lee
‡Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 91125, United States.
P James
PJ
Schuck
†Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Peter S
PS
Nico
†Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Benjamin
B
Gilbert
maghemite; magnetite; nanoparticle; rutile organic molecules; surface enhanced Raman spectroscopy