Metasurface Technologies for Optical Sensing Applications

The rapid evolution of metasurface technologies is revolutionising optical sensing by enabling unprecedented control over light–matter interactions at subwavelength scales. Metasurfaces consist of ultrathin arrays of engineered meta-atoms in dielectric or metallic platforms that shape amplitude, phase and polarisation with high spatial resolution. By tailoring the geometry and arrangement of nanoresonators, these surfaces achieve high-quality-factor resonances, bound states in the continuum and Fano interference, which together amplify near fields and sharpen spectral features. This level of control has led to compact, label-free sensors capable of detecting molecular vibrations, refractive-index changes, genetic fragments and extracellular biomarkers with femtomolar sensitivity. Advances in continuous spectral encoding and multiplexed platforms further permit real-time analysis of complex analyte mixtures without bulk optics. Such metasurface-enabled devices promise transformative applications in point-of-care diagnostics, environmental monitoring and chemical analysis, offering miniaturised, low-power alternatives to traditional spectrometers. Ongoing research explores integration with microfluidics, CMOS readouts and smart polymers, underscoring the global significance of metasurfaces for next-generation optical sensing networks.

Research from Nature Portfolio

Recent studies have introduced dual-gradient metasurfaces comprising smoothly varying arrays of nanoresonators that continuously map the spectral–quality-factor parameter space. This approach generates tens of thousands of distinct resonant modes within a compact footprint, optimising surface-enhanced spectroscopy for molecular detection across varying concentrations. In another development, high-Q silicon nanoantennas have been functionalised for label-free genetic screening, demonstrating femtomolar sensitivity for viral gene fragments within minutes and paving the way for amplification-free, multiplexed molecular assays. Complementing these efforts, diatomic dielectric metasurfaces supporting bound states in the continuum have been integrated into optofluidic imaging setups, providing single-wavelength detection of extracellular vesicles with high figures of merit and real-time monitoring capabilities. Together, these works exemplify the translation of metasurface design principles into robust, high-performance sensing platforms.

Metasurface Technologies for Optical Sensing Applications publication trend

The graph below shows the total number of articles in metasurface technologies for optical sensing applications across all publications each year (not limited to Nature Index journals).

Technical terms

Metasurface: An ultrathin arrangement of subwavelength meta-atoms engineered to control light properties such as phase, amplitude and polarisation.

Quality factor (Q-factor): A dimensionless parameter quantifying the sharpness of a resonance, defined as the ratio of stored to dissipated energy per cycle.

Bound state in the continuum (BIC): A resonant mode that remains confined despite lying within the spectrum of radiative states, yielding exceptionally high Q-factors.

Fano resonance: An asymmetric spectral line-shape arising from interference between a discrete resonance and a continuum of modes, enhancing sensitivity to perturbations.

Nanoantenna: A subwavelength resonator designed to concentrate and manipulate electromagnetic fields at nanoscale dimensions for enhanced sensing.

References

1. Tailoring Light–Matter Interactions in Overcoupled Resonator for Biomolecule Recognition and Detection. Nano-Micro Letters (2024).
2. Continuous spectral and coupling-strength encoding with dual-gradient metasurfaces. Nature Nanotechnology (2024).
3. Frequency selective fingerprint sensor: the Terahertz unity platform for broadband chiral enantiomers multiplexed signals and narrowband molecular AIT enhancement. PhotoniX (2023).
4. Rapid genetic screening with high quality factor metasurfaces. Nature Communications (2023).
5. Imaging-based spectrometer-less optofluidic biosensors based on dielectric metasurfaces for detecting extracellular vesicles. Nature Communications (2021).
6. Ultrasensitive specific sensor based on all-dielectric metasurfaces in the terahertz range. RSC Advances (2020).