Plasmonic Exosome Biosensors for Medical Diagnostics

This chapter provides an overview of plasmonic biosensor technology for the analysis of extracellular lipid vesicles that hold potential to serve as new type of biomarkers. In particular, it discusses detection of exosomes that are secreted to bodily fluids and become of increasing interest in clinical research. Plasmonic biosensor technology is pushed forward to provide new means for their sensitive and specific detection without the need of specialized laboratories. It offers a versatile optical toolbox for probing various biological species by tightly confined electromagnetic field of surface plasmons. These optical waves originate from collective oscillations of electron charge density at metallic thin films and (nano) structures. This chapter gives an introduction to surface plasmon photonics and its use in direct surface plasmon resonance and in fluorescence spectroscopy-based biosensors. It provides a brief summary of current state-of-the-art in exosome biomarker research and discusses current advances in exosome plasmonic biosensors for medical diagnostics of diseases, in particular cancer.