Plasmonic Sensing Techniques in High-Pressure Environments

Plasmonic sensing techniques exploit the collective oscillations of conduction electrons at the surfaces of noble metal nanostructures to probe local physical and chemical changes. When subjected to high pressures, these oscillations—or localized surface plasmon resonances (LSPRs)—shift in wavelength due to modifications in electron density and the refractive index of the surrounding medium. Diamond anvil cells (DACs) routinely generate pressures exceeding tens of gigapascals, enabling in situ investigation of phase transitions, solvent solidification and material compressibility. Under hydrostatic conditions, plasmonic probes report on uniform compression, while non-hydrostatic stresses introduce directional shear that can fragment anisotropic particles such as nanorods. By monitoring LSPR shifts or extinction spectra in real time, researchers can map pressure-dependent changes in density, detect first-order transitions and assess the mechanical resilience of colloidal sensors. These approaches hold promise for deep-earth geophysics, high-pressure chemistry, material synthesis under extreme conditions and the design of sensors for harsh industrial or sub-sea environments.

Research from Nature Portfolio

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Research from all publishers

Studies on PEGylated gold nanoparticles dispersed in ethanol–methanol mixtures under hydrostatic compression have used pressure-dependent LSPR measurements to track solvent solidification. Results reveal a linear reduction in the solidification pressure with increasing nanoparticle concentration and allow precise determination of high-pressure ethanol densities in both liquid and crystalline phases.

In situ small-angle X-ray scattering (SAXS) experiments have characterised the pressure-induced morphological evolution of gold nanorods and nanospheres. Nanorods maintain aspect ratio up to solvent freezing, after which anisotropic stresses drive diffusion, aggregation and irreversible clustering. Quantitative analysis of form and structure factors elucidates shape-dependent aggregation pathways under high pressure.

A combined study of optical absorption spectroscopy and transmission electron microscopy under non-hydrostatic pressures up to 30 GPa has explored the correlation between spectroscopic signatures and mechanical stability of gold nanocrystals. While nanospheres exhibit remarkable morphological resilience, nanorods undergo shear-induced fragmentation, yet colloidal stability persists across the applied pressure range, underscoring their potential as robust in situ probes.

Plasmonic Sensing Techniques in High-Pressure Environments publication trend

The graph below shows the total number of articles in plasmonic sensing techniques in high-pressure environments across all publications each year (not limited to Nature Index journals).

Technical terms

Localized surface plasmon resonance (LSPR): Resonant oscillation of conduction electrons at a nanoparticle surface induced by incident light.

Diamond anvil cell (DAC): High-pressure device employing two opposing diamonds to generate extreme pressures on a sample.

Hydrostatic pressure: Uniform pressure applied equally in all directions without directional stress components.

Non-hydrostatic pressure: Pressure with directional components causing shear stresses in a sample.

Bulk modulus: Measure of a material’s resistance to uniform compression, expressed as pressure per unit volume change.

Small-angle X-ray scattering (SAXS): Technique probing nanoscale structural evolution by measuring X-ray scattering at low angles.

References

1. The influence of PEGylated gold nanoparticles on the solidification of alcohols. Journal of Materials Chemistry C (2024).
2. Behavior of Au Nanoparticles under Pressure Observed by In Situ Small-Angle X‑ray Scattering. ACS Nano (2022).
3. Correlation between Spectroscopic and Mechanical Properties of Gold Nanocrystals under Pressure. The Journal of Physical Chemistry C (2022).