We have a large program to explore the use of glycans for sensing and delivery applications. By installing glycans, using a polymeric tether, onto gold nanorods we can exploit their unique optical properties, allowing us to detect if a protein binds to the glycans. Rod-shaped (compared to spherical) gold particles are exciting, as they have an additional SPR ('colour') band, which does not overlap wiht the background from e.g. blood/serum, unlike spherical gold. In our latest paper we explore how the proteins found in serum can impact on this biosensing due to non-specific fouling (sticking to form a biocorona) to the particle surface. This is a major challenge in nanomedicine/diagnostics as this fouling always occurs. Indeed, we observed that serum proteins do bind to the nanoparticles, and compared the biosensing in comparison to a model buffer solution. Interestingly, despite the biocorona formation we could still detect a lectin (glycan binding protein) BUT, it was show that the response was due to displacement of the biocorona. This meant that after binding there was less mass on the surface, than before, which was not expected. This displacement mechanism is useful as it shows our polymer-tethering strategy can be used to prepare nanoparticles suitable for use in complex media. This was a collaboration with VITO in belgium as part of a EU wide project.

Read the paper here

The Polymeric Glyco-Linker Controls the Signal Outputs for Plasmonic Gold Nanorods Biosensors due to Biocorona Formation