Plasmonic Properties of Metal Nanoparticles

Metal nanoparticles support resonant oscillations of conduction electrons known as localized surface plasmons, giving rise to pronounced optical absorption and scattering in the visible and near-infrared regions. These resonances generate intense near-field enhancements that can be exploited for applications in chemical and biological sensing, photocatalysis, photovoltaics and integrated nano-optical devices. The resonance frequency and field distribution are highly sensitive to particle size, shape, composition and the surrounding dielectric environment. Noble metals such as gold and silver have been the primary focus because of their low optical losses and tunable resonances; however, earth-abundant alternatives (copper, aluminium) are increasingly investigated despite challenges in oxidation and stability. Advances in synthetic control—chemical reduction, laser ablation and lithographic patterning—enable precise tuning of morphology from spheres and rods to prisms and core–shell architectures. Characterisation techniques, including electron-energy-loss spectroscopy and cathodoluminescence, elucidate spatial distributions of plasmon modes and their ultrafast decay dynamics. Strategies to stabilise reactive metals through tailored ligands or shell encapsulation are overcoming limitations in ambient stability. The interplay between far-field optical properties and ultrafast carrier dynamics underpins emerging applications in nonlinear optics, optical limiting and ultrafast switching. Continued integration with photonic and electronic platforms offers routes to high-sensitivity biosensing, efficient light harvesting and on-chip optical circuitry, driving global interest in plasmonic nanomaterials across disciplines.

Research from Nature Portfolio

Recent studies have shown that ambient oxidation and carbon contamination dramatically reduce the intensity and reproducibility of surface-enhanced Raman scattering on silver substrates, with oxidation causing rapid decay of plasmon-mediated signal enhancement and increased variability. Investigations into copper nanoparticles have revealed that short-chain thiolate ligands bearing hydrophilic end groups can effectively retard air-induced oxidation without electrical isolation, thereby preserving plasmon resonance characteristics and enabling the exploration of size-dependent work-function scaling. These foundational findings address stability challenges and clarify the correlation between surface chemistry and plasmonic performance in reactive metal nanoparticles.

Plasmonic Properties of Metal Nanoparticles publication trend

The graph below shows the total number of articles in plasmonic properties of metal nanoparticles across all publications each year (not limited to Nature Index journals).

Technical terms

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

Surface-enhanced Raman scattering (SERS): Amplification of Raman signals due to enhanced electromagnetic fields near plasmonic nanostructures.

Work function: Minimum energy required to remove an electron from a solid to a point in vacuum immediately outside its surface.

Thiolate capping ligand: Organic molecule terminating in a thiol group used to stabilise metal nanoparticle surfaces and modify chemical reactivity.

Electron-energy-loss spectroscopy (EELS): Technique measuring energy lost by electrons traversing a specimen, used to characterise plasmon resonances at nanometre resolution.

References

1. Disordered plasmonic system with dense copper nano-island morphology. Nanophotonics (2025).
2. Cu metal nanoparticles in transparent electrodes for light harvesting in solar cells. Applied Surface Science (2024).
3. Atmospheric oxidation and carbon contamination of silver and its effect on surface-enhanced Raman spectroscopy (SERS). Scientific Reports (2016).
4. Retarding oxidation of copper nanoparticles without electrical isolation and the size dependence of work function. Nature Communications (2017).
5. Corrosion processes of silver nanoparticles. Applied Nanoscience (2022).
6. Nonlinear Optical Properties, Optical Limiting and Optical Switching of Ag Nanoparticles Prepared by a Green Synthetic Method. Optics and Photonics Journal (2018).