Plasmonic biosensing

Custom Hybrid Nanostructure Design
We engineer plasmonic substrates that go beyond flat metal films by:

  • Fabricating multiperiodic and aperiodic nanopatterns (rings, holes, gratings) via electron-beam and nanoimprint lithography
  • Leveraging finite-element-method (FEM) and rigorous coupled-wave analysis (RCWA) simulations to tune resonance wavelengths and field enhancements
  • Iterating designs with genetic- and gradient-based algorithms to maximize figure-of-merit under real-world conditions

Surface Chemistry & Biofunctionalization
Our surface-anchoring strategies ensure stable, specific capture of target analytes by:

  • Forming self-assembled monolayers of mixed amine-/thiol-terminated linkers on gold
  • Immobilizing antibodies, aptamers, or molecularly imprinted polymers with controlled orientation
  • Applying optimized blocking layers to suppress non-specific adsorption and matrix interference

Advanced Optical Readout & Data Processing
We extract meaningful signals from complex plasmonic responses through:

  • Real-time spectral or refractive index tracking with custom microfluidic flow cells
  • Multivariate calibration (PCA, PLS) to deconvolute overlapping peaks and isolate signature shifts
  • Machine-learning techniques that compensate for nonlinearities, drift, and experimental noise and take into account the plurality of parameters and information encrypted in plasmonic resonances 

Direct Observation of Plasmonic Modes
Our homemade Fourier-plane spectroscopy setup enables:

  • Angularly resolved mapping of scattering and transmission to visualize plasmonic dispersion
  • Real-time capture of mode intensity distributions across the back focal plane
  • Correlation of observed angular features with nanostructure geometry and resonant hotspots

Targeted Applications
Our platform is tailored for:

  • Biomedical Diagnostics: ultra-low-volume detection of proteins, nucleic acids, and exosomes in plasma or whole blood
  • Food Quality & Safety: rapid screening of pesticides, allergens, and spoilage markers in complex matrices
  • Environmental Monitoring: onsite quantification of heavy metals, pollutants, and pathogens in water and air samples

Collaborative Computational & Experimental Framework
In partnership with the Computational Materials and Photonics Group at the University of Kassel, we:

  • Integrate multiscale modelling of plasmonic–molecule interactions
  • Validate simulation predictions through high-resolution SEM and optical characterization
  • Continuously refine our workflows via closed-loop feedback between computation and experiment

Publications

1. J. Etxebarria-Elezgarai, L. Bergamini, E. Lopez, M. Morant-Minana, J. Adam, N. Zabala, J. Aizpurua and A. Seifert
Small Methods 8, 2301445 (2024)

2. M. Charconnet, M. Korsa, S. Petersen, J. Plou, C. Hanske, J. Adam and A. Seifert
Small Methods 7, (2023)

3. J. Plou, M. Charconnet, I. Garcia, J. Calvo and L. Liz-Marzan
ACS Nano 15, 8984 (2021)