Localized Surface Plasmon Resonance Biosensing Techniques

Localized surface plasmon resonance (LSPR) biosensing exploits the resonant oscillation of conduction electrons in metallic nanostructures when excited by light. Shifts in the characteristic extinction or scattering spectrum arise upon binding of analytes within the near‐field region, enabling label-free, real-time detection with high sensitivity. Tailoring nanoparticle composition, size and geometry allows spectral tuning from the visible to near-infrared and optimisation of field enhancement. Diverse platforms include colloidal nanoparticles, lithographically defined nanostructures, optical-fibre probes and metasurfaces. Applications span clinical diagnostics, environmental monitoring and food safety, where low-cost, portable and multiplexed assays are increasingly demanded. Key challenges involve reproducible fabrication, stability in complex media and integration with microfluidics and data-analysis tools. Emerging directions encompass hybrid photonic–plasmonic systems, machine-learning-driven spectral interpretation and quantum-inspired sensitivity enhancements.

Research from Nature Portfolio

Gold nanoparticle–aptamer LSPR sensing chips have been devised for ultra-sensitive detection of Salmonella typhimurium in food matrices. Monolayers of 20 nm gold nanoparticles are self-assembled on transparent substrates and functionalised with specific aptamers, yielding longitudinal extinction shifts upon bacterial binding. The platform achieves a limit of detection of ~1 × 10^4 cfu/mL in pork samples within 30–35 minutes without pre-enrichment and exhibits robustness against matrix effects. Separately, capped gold nanoslit arrays fabricated by thermal-embossing nanoimprint on polymer films demonstrate enhanced Fano resonances arising from coupling between cavity and plasmon modes. Optimised slit dimensions produce asymmetric line-shapes with full-width at half-maximum below 4 nm, wavelength sensitivities approaching 1,000 nm/RIU and figures of merit above 250, enabling ultra-sharp, label-free refractometric biosensing in a low-cost, high-throughput format.

Research from all publishers

A recent review of surface plasmon resonance technology outlines advances in instrumentation, including prism-coupled, grating and fibre-optic SPR and LSPR devices. It discusses case studies in life sciences, pharmaceutical screening, agrifood safety and environmental analysis, emphasising the evolution towards miniaturised, automated and multiplexed systems. Limitations such as sensor stability, throughput and integration with sample handling are analysed alongside future trends in wearable and disposable sensors. Complementing this, a waveguide-enhanced nanogold-linked immunosorbent assay (WENLISA) employs sandwich immunoassays on a plasmonic waveguide: capture antibodies anchor the target, detection antibodies conjugated to gold nanoparticles induce evanescent-field redistribution and strong nanoplasmonic absorption. This approach achieves a record limit of detection of 48.7 fg/mL for procalcitonin in under eight minutes and demonstrates clinical feasibility in sepsis diagnosis from blood plasma samples.

Localized Surface Plasmon Resonance Biosensing Techniques publication trend

The graph below shows the total number of articles in localized surface plasmon resonance biosensing techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Localized Surface Plasmon Resonance (LSPR): Resonant oscillation of conduction electrons confined to metallic nanoparticles or nanostructures, producing strong near-field enhancement and refractive index-dependent spectral shifts.

Evanescent field: Decaying electromagnetic field that extends from a plasmonic surface into the adjacent medium, whose intensity is altered by local refractive index changes.

Figure of merit (FOM): Ratio of spectral sensitivity (wavelength shift per refractive index unit) to resonance linewidth, indicating the precision of a plasmonic sensor.

Limit of detection (LOD): Lowest analyte concentration that can be reliably distinguished from the background noise at a defined confidence level.

Aptamer: Short, single-stranded nucleic acid ligand that binds selectively to a target molecule and serves as a recognition element in biosensors.

Fano resonance: Asymmetric spectral feature arising from interference between a discrete resonance and a continuum mode, yielding narrow linewidths and high sensitivity.

References

1. Development of gold nanoparticle-aptamer-based LSPR sensing chips for the rapid detection of Salmonella typhimurium in pork meat. Scientific Reports (2017).
2. Ultrasensitive Biosensors Using Enhanced Fano Resonances in Capped Gold Nanoslit Arrays. Scientific Reports (2015).
3. Surface plasmon resonance technology: Recent advances, applications and experimental cases. TrAC Trends in Analytical Chemistry (2023).
4. Ultrasensitive and Rapid Detection of Procalcitonin via Waveguide-Enhanced Nanogold-Linked Immunosorbent Assay for Early Sepsis Diagnosis. Nano Letters (2024).