Nanoparticle Plasmonics for Surface-Enhanced Spectroscopy

Nanoparticle plasmonics harnesses the interaction of light with conduction electrons in metallic nanostructures to generate intense, localised electromagnetic fields. When two or more nanoparticles are placed in close proximity, coupling of their localised surface plasmon resonances creates ‘hotspots’ where field enhancements may exceed several orders of magnitude. These hotspots underpin surface-enhanced Raman scattering (SERS), enabling the detection of minute quantities of molecular species through amplified vibrational fingerprints. Control over particle size, shape, composition and assembly geometry allows tuning of resonance wavelengths across the visible and near-infrared regions, facilitating applications from single-molecule biosensing to environmental monitoring and anticounterfeiting. Emerging approaches integrate template scaffolds, magnetic alignment and photoresponsive chemistry to produce reconfigurable, multiplexed and programme-tunable spectroscopic substrates, thereby broadening the functional scope of plasmonic sensors and advancing practical deployment in biomedical diagnostics, chemical analysis and materials characterisation.

Research from Nature Portfolio

Recent studies have demonstrated that DNA origami scaffolds facilitate the assembly of gold nanorods into tip-to-tip dimers with optimised ~8 nm interparticle gaps, yielding accessible plasmonic hotspots for label-free detection of individual proteins via SERS with sub-second acquisition times. Work on magnetically manipulable hybrid nanorods has extended this capability by coupling magnetic and plasmonic anisotropy, allowing controlled alignment in polymer matrices and mechanochromic spectral tuning under applied fields. Complementary efforts in supramolecular nanoassemblies have produced multiplexed SERS platforms capable of quantitative analysis of multiple small molecules in complex aqueous environments with high reproducibility and minimal sample preparation.

Nanoparticle Plasmonics for Surface-Enhanced Spectroscopy publication trend

The graph below shows the total number of articles in nanoparticle plasmonics for surface-enhanced spectroscopy across all publications each year (not limited to Nature Index journals).

Technical terms

Localised surface plasmon resonance (LSPR): Collective oscillation of conduction electrons in a metal nanoparticle induced by incident light, leading to strong absorption and scattering.

Hotspot: A nanoscale region of intense electromagnetic field enhancement typically found in the junction between closely spaced nanoparticles.

Surface-enhanced Raman scattering (SERS): A spectroscopic technique that exploits plasmonic field enhancements to amplify the Raman signals of molecules adsorbed on or near metal nanostructures.

DNA origami: A nanofabrication method that folds DNA into predefined shapes to serve as scaffolds for precise positioning of nanoparticles.

Anisotropy: Direction-dependent physical properties, such as differences in plasmonic response along different axes of an elongated nanoparticle.

References

1. Dichroic switching of core–shell plasmonic nanoparticles on reflective surfaces. Exploration (2023).
2. Accessible hotspots for single-protein SERS in DNA-origami assembled gold nanorod dimers with tip-to-tip alignment. Nature Communications (2023).
3. Quantitative multiplexing with nano-self-assemblies in SERS. Scientific Reports (2014).
4. Optimal Size of Gold Nanoparticles for Surface‐Enhanced Raman Spectroscopy under Different Conditions. Journal of Nanomaterials (2013).
5. Plasmonic Nanoassemblies: Tentacles Beat Satellites for Boosting Broadband NIR Plasmon Coupling Providing a Novel Candidate for SERS and Photothermal Therapy. Small (2020).
6. Coupling magnetic and plasmonic anisotropy in hybrid nanorods for mechanochromic responses. Nature Communications (2020).
7. Light-Directed Tuning of Plasmon Resonances via Plasmon-Induced Polymerization Using Hot Electrons. ACS Photonics (2017).