Manipulating Coupled Field Enhancement in Slot-under-Groove Nanoarrays for Universal Surface-Enhanced Raman Scattering

Abstract

Surface-enhanced Raman scattering (SERS) is an ultrasensitive spectroscopic technique that can identify materials and chemicals based on their inelastic light-scattering properties. In general, SERS relies on sub-10 nm nanogaps to amplify the Raman signals and achieve ultralow-concentration identification of analytes. However, largesized analytes, such as proteins and viruses, usually cannot enter these tiny nanogaps, limiting the practical applications of SERS. Herein, we demonstrate a universal SERS platform for the reliable and sensitive identification of a wide range of analytes. The key to this success is the prepared "slot-under-groove" nanoarchitecture arrays, which could realize a strongly coupled field enhancement with a large spatial mode distribution via the hybridization of gap-surface plasmons in the upper V-groove and localized surface plasmon resonance in the lower slot. Therefore, our slot-under-groove platform can simultaneously deliver high sensitivity for small-sized analytes and the identification of large-sized analytes with a large Raman gain.

Preparation and investigation of high-performance flexible and transparent Ag/PDMS substrate with the bionic structure of cicada wings

“…Such strong enhancement could be ascribed to the much more surface area as well as hotspots provided by those protuberant nanopillars. In addition, the gaps between the nanopillars, as indicated by the white arrows in figure 3(c), were also effective hotspots [27], further boosting the SERS enhancement.…”

Ordered Anodic Aluminum Oxide-Based Nanostructures for Surface-Enhanced Raman Scattering: A Review

“…After growing active materials directly in AAO nanopores, it is also feasible to remove the AAO template. Yan et al introduced a “slot-under-groove” Au nanoarchitecture array, which served as a versatile SERS platform embracing a variety of targets over a wide size range . By duplicating the nanopores of V-shaped AAO template, the proposed Au nanoarrays enable coupled SERS enhancement with a large spatial mode distribution through the strong hybridization of gap-surface plasma in the upper V-groove and LSPR in the lower slot.…”

“…For the purpose of adapting to complex testing environments, researchers have reported efficient preparation and modulation of flexible SERS substrates via AAO templates . Yan et al fabricated a Au-coated PMMA nanostructure and replicated the nanopores of the I-AAO template (Figure d) . This unique slot-under-groove nanoarray has a good SERS biosensing performance for the Aβ peptide.…”

“…Copyright 2022, Elsevier. Adapted with permission from ref . Copyright 2023, American Chemical Society.…”

Contractible Plasmonic Nanospheres Array with Dynamically Tailorable Gap Size for Molecule Trapping and Sensitive SERS Detection

“…Accurate delivering the target molecules into these hot spots remains a significant challenge for two reasons: i) narrower nanogaps can produce a stronger local electromagnetic field, but they also restrict the entry of molecules due to the steric hindrance effect, particularly when the gap size is comparable to typical sizes of molecules; [23,24] and ii) such a tiny active region (referred to as effective volume) only occupies a small fraction of the entire SERS substrate, reducing the possibility of analytes reaching the hot spot region. [22,25,26] Therefore, in addition to creating high-density hot spots or hot spots with a large spatial mode distribution to increase the potential for analytes falling into them, [27,28] it is also critical to actively trap analytes into hot spots to improve the SERS sensing efficiency. An effective way to address this issue is to deliver the analytes prior to forming the nanogaps.…”