Plasmonic Biosensing Techniques for Nanoscale Pathogen Detection

Plasmonic biosensing harnesses the resonant interaction between light and free electrons at metallic interfaces to detect minute changes in refractive index arising from molecular binding events. By exploiting surface plasmon resonance (SPR) and its localised counterpart (LSPR) in engineered nanostructures—ranging from gold nanoparticles and nanohole arrays to photonic crystals—researchers have achieved label-free, real-time detection of pathogens at nanometre scales. These platforms can register shifts in optical spectra or phase induced by target binding, enabling quantification of viruses, bacteria and single-cell secretions with sensitivities down to picomolar or even attomolar concentrations. Integration with microfluidics and machine-learning algorithms has further advanced throughput and specificity, supporting point-of-care diagnostics and environmental surveillance. The global significance of this work lies in its potential to deliver rapid, cost-effective assays for emerging infectious diseases, antimicrobial resistance monitoring and biothreat detection, thereby strengthening public health responses worldwide.

Research from Nature Portfolio

Recent studies have demonstrated a high-throughput plasmonic microwell array for spatiotemporal profiling of single-cell secretions. The device comprises a gold film perforated with nanometric holes functionalised with specific receptors and interrogated by light matching its extraordinary optical transmission spectrum. Binding events around secreting cells induce SPR shifts that are recorded as intensity variations by a camera, while machine-learning-assisted cell tracking compensates for cellular motion. This approach enables parallel monitoring of hundreds of cells, revealing heterogeneity in antibody secretion profiles.

A comprehensive review of virus diagnostics has synthesised advances in propagating SPR, LSPR, surface-enhanced Raman scattering, surface-enhanced fluorescence and surface-enhanced infrared absorption spectroscopy. By collating performance metrics—such as sensitivity, dynamic range and assay time—the analysis provides a framework for the rational design of next-generation plasmonic sensors capable of rapid, multiplexed detection of viral pathogens in complex matrices.

Research from all publishers

Investigations into gold nanoparticles (AuNPs) have highlighted their role as signal transducers in virus detection. Biofunctionalised AuNPs, with tailored core geometries and surface chemistries, amplify optical responses through LSPR and aggregation-induced colour changes. Studies have documented dramatic enhancements in sensitivity and detection speed across assay formats, including lateral flows and microplate readers, pointing towards scalable in-field diagnostic applications.

A phase-sensitive plasmonic biosensor employing Au nanohole arrays and a lens-free interferometric microarray imager offers label-free detection of angstrom-scale topographical changes over large areas. By measuring phase shifts of high-quality-factor resonances in a collinear optical path, the platform achieves ultrasensitive biomarker quantification across thousands of array elements. Its low-cost, off-the-shelf components render it suitable for point-of-care deployment.

Plasmonic Biosensing Techniques for Nanoscale Pathogen Detection publication trend

The graph below shows the total number of articles in plasmonic biosensing techniques for nanoscale pathogen detection across all publications each year (not limited to Nature Index journals).

Technical terms

Surface plasmon resonance (SPR): Resonant oscillation of conduction electrons at a metal–dielectric interface sensitive to refractive-index changes.

Localized surface plasmon resonance (LSPR): SPR confined to metal nanoparticles, producing intense local electromagnetic fields and spectral sensitivity to particle environment.

Surface-enhanced Raman scattering (SERS): Raman signal enhancement via plasmonic nanostructures, enabling molecular fingerprinting at low concentrations.

Nanohole array: Periodic array of nanoscale apertures in a metal film that supports extraordinary optical transmission and plasmonic sensing.

Interferometric microarray imaging: Label-free detection technique recording phase variations of light transmitted through or reflected from plasmonic structures.

Gold nanoparticle (AuNP): Colloidal gold structures exhibiting LSPR, widely used for optical biosensing and signal amplification.

References

1. High-throughput spatiotemporal monitoring of single-cell secretions via plasmonic microwell arrays. Nature Biomedical Engineering (2023).
2. A comprehensive review on plasmonic-based biosensors used in viral diagnostics. Communications Biology (2021).
3. Applications of gold nanoparticles in virus detection. Theranostics (2018).
4. Phase-sensitive plasmonic biosensor using a portable and large field-of-view interferometric microarray imager. Light: Science & Applications (2017).