On-chip surface-enhanced Raman spectroscopy using nanosphere-lithography patterned antennas on silicon nitride waveguides

Abstract

Abstract:A hybrid integration of nanoplasmonic antennas with silicon nitride waveguides enables miniaturized chips for surface-enhanced Raman spectroscopy at visible and near-infrared wavelengths. This integration can result in high-throughput SERS assays on low sampling volumes. However, current fabrication methods are complex and rely on electron-beam lithography, thereby obstructing the full use of an integrated photonics platform. Here, we demonstrate the electronbeam-free fabrication of gold nanotriangles on deep-UV patterned silicon nitride waveguides using nanosphere lithography. The localized surface-plasmon resonance of these nanotriangles is optimized for Raman excitation at 785 nm, resulting in a SERS substrate enhancement factor of 2.5 × 10 5 . Furthermore, the SERS signal excited and collected through the waveguide is as strong as the free-space excited and collected signal through a high NA objective.

Plasma-Enhanced Atomic Layer Deposition of Nanostructured Gold Near Room Temperature

“…To investigate this, we estimated the number of measured pNTP molecules on each sample based on an estimate of the accessible gold surface area and the reported adsorption density for pNTP on gold (see the Supporting Information). 36 We found no significant difference in the estimated number of adsorbed pNTP molecules when comparing the four ALD samples. This suggests that a difference in the number of measured pNTP molecules cannot solely explain the observed differences in the SERS signal intensity.…”

Chip-Based Resonance Raman Spectroscopy Using Tantalum Pentoxide Waveguides

“…One interesting approach is to use surface enhanced Raman scattering (SERS), which can give a signal increase of many orders of magnitude. Several approaches have been studied for SERS implementation, including the use of nanoporous gold [15] and gold bow-tie antenna [16]. A challenge with SERS is that it requires surface treatments that can generate hot spots and reduce life-time.…”

Hedgehog Inspired CuO Nanowires/Cu2O Composites for Broadband Visible‐Light‐Driven Recyclable Surface Enhanced Raman Scattering

“…Among them, laser processing is an intriguing approach to fabricate micro/nanostructures over a large area at a high speed . Nevertheless, most of these traditional SERS substrates can only be applied as single use due to the cross‐contamination of probe molecules . The high costs also hinder the practical applications of large‐scale production of noble metal‐based SERS substrates.…”