Au Bowtie Nanostructures for Surface-enhanced Raman Spectroscopy

Designing nanostructures for surface-enhanced Raman spectroscopy (SERS) is an active area of research because of the potential for chemical sensing with single-molecule sensitivity. We report preliminary SERS measurements on Au bowtie structures with nanometer size interelectrode gaps fabricated by electromigration. Initial data suggest that the bowtie structure provides a large electromagnetic enhancement for SERS over a small volume, enabling few or single molecule spectroscopy. The local plasmon resonance of the bowtie structure is tunable by varying the width of the gap between the two halves using electromigration. Additionally we report on a multiple bowtie structure that combines several bowtie devices in parallel allowing for the simultaneous electromigration of several devices at once to similar gap sizes.