Antibody binding to plasmonic nanostructure: A validation study using experiment and simulation

Localized surface plasmon resonance (LSPR) sensors allow the label-free detection of molecules in real-time with a high sensitivity, which makes them suitable for the detection of various molecules. However, the experimental characterization of the surface functionalization and the molecular binding on the nanostructured sensor surface represent black boxes. To overcome these uncertainties, this study shows an approach to simulate and experimentally validate the plasmonic response upon molecular binding to a LSPR sensor for the detection of diclofenac (DCF). Assuming homogeneous molecular coverage and averaged parameters such as refractive index and layer thickness through the combination of an iterative experimental validation and electrodynamics simulations a coherent model was formed that includes the uncertainties of molecular binding. This validated model and the obtained parameter for the biochemical assay forms the basis for a future automated optimization of the nanostructure geometry with respect to increased sensitivity to molecular binding.