SERS from Graphene in the Presence of Magnetic Nanoparticles Fe3O4/Au

The continuous scaling of electronic devices leads to the necessity of controlling the structure of low-dimensional materials. Surface-enhanced Raman spectroscopy (SERS) is the technique of choice for studying the crystallinity, composition, and mechanical properties of nanomaterials. Surface-enhanced Raman scattering (SERS) utilizes the electromagnetic field generated by localized surface plasmon resonances (LSPR) in metal nanostructures to enhance the optical response from the sample. Previously the SERS activity of graphene placed on a substrate with an array of gold nanodisks was demonstrated and the enhancement of the main vibrational modes up to 50 times was achieved. Taking into account these results an approach for further improvement of the technique is suggested. It is known that SERS enhancement factor (EF) is dependent on the gap between a metal particle and a sample. In the present study, we exploited the magnetic properties of $\mathrm{Fe3O4} / \mathrm{Au}$ nanoparticle aggregates to make closer contact between the graphene film and the gold nanostructures on the Si substrate in the presence of an external magnetic field. Such an approach resulted in increasing the intensity of graphene G mode with the enhancement factor of 5. The first findings and further perspectives on the study are discussed.