Magneto-plasmonic nanoparticles for SERS

The goal of this study is development of ultra-sensitive and reproducible SERS platform based on novel magnetoplasmonic nanoparticles produced by laser ablation. The magnetic part of hybrid nanoparticles ensures manipulation of the nanoparticles by magnetic field by arranging them at biological surfaces in a special geometry resulting in high and reproducible SERS. Magneto-plasmonic Au-Fe nanoparticles in colloidal suspension were prepared by picosecond laser ablation of evaporated iron and gold films on glass. The nanoparticles were characterized by UV-visible extinction, high resolution electronic microscopy, and Raman spectroscopy. EDX analysis revealed that the shell of nanoparticles (2−20 nm) consist of iron and the core is composed mostly of gold. The plasmonic behavior of nanoparticles was accessed by analysis of SERS spectra from adsorbed adenine as probe ligand. The fabrication of hybrid nanoparticles by laser ablation offers a new possibility for construction of SERS substrates with tunable optical and magnetic properties for biomedical sensing.