Plasmonic Sensing

The Molecular Plasmonics group develops nanophotonic and plasmonic approaches for single-molecule detection using a single particle−single molecule approach.

The Molecular Plasmonics group develops nanophotonic and plasmonic approaches for single-molecule detection using a single particle−single molecule approach.

The Molecular Plasmonics group (www.molecular-plasmonics.nl) develops nanophotonic and plasmonic approaches for single-molecule detection using a single particle−single molecule approach. Single-molecule detection has long relied on fluorescent labelling with high quantum-yield fluorophores. Plasmonic and nanophotonic structures provide a means to enhance weak fluorescent signals and have even enabled label-free detection of single proteins. The ability to detect and study biomolecules using plasmonic structures is facilitated by the electric field associated with the plasmon resonance. This field penetrates the medium around the particle and enhances the interaction between a molecule and the particle’s plasmon.

This plasmon−molecule interaction provides two pathways for sensing: first, by exploiting the effect of the plasmon on the molecule leading to enhancement (or quenching) of the molecule’s fluorescence. Secondly, sensing can be implemented by exploiting the effect of the molecule on the plasmon leading to frequency shifts of the plasmon resonance. The Molecular Plasmonics group develops novel sensing concepts based on both mechanisms using a correlative microscopy approach. In the lab we employ techniques such as single-particle spectroscopy, super-resolution microscopy, atomic force microscopy, and numerical modelling.

These sensing concepts are then applied toward fundamental biophysical studies of molecular dynamics (interaction kinetics, conformational dynamics, enzymology), and toward societally relevant applications such as the detection of biomarkers in healthcare, contamination in the environment, and nutrients in food processes. To maximize the application potential of our sensors we are integrated in the Institute for Complex Molecular Systems (ICMS) and the Institute for Photonic Integration (IPI) at TU/e.