title: Glycan heterogeneity on gold nanoparticles increases lectin discrimination capacity in label-free multiplexed bioassays.
abstract: The development of new analytical tools as point-of-care biosensors is crucial to combat the spread of infectious diseases, especially in the context of drug-resistant organisms, or to detect biological warfare agents. Glycan/lectin interactions drive a wide range of recognition and signal transduction processes within nature and are often the first site of adhesion/recognition during infection making them appealing targets for biosensors. Glycosylated gold nanoparticles have been developed that change colour from red to blue upon interaction with carbohydrate-binding proteins and may find use as biosensors, but are limited by the inherent promiscuity of some of these interactions. Here we mimic the natural heterogeneity of cell-surface glycans by displaying mixed monolayers of glycans on the surface of gold nanoparticles. These are then used in a multiplexed, label-free bioassay to create 'barcodes' which describe the lectin based on its binding profile. The increased information content encoded by using complex mixtures of a few sugars, rather than increased numbers of different sugars makes this approach both scalable and accessible. These nanoparticles show increased lectin identification power at a range of lectin concentrations, relative to single-channel sensors. It was also found that some information about the concentration of the lectins can be extracted, all from just a simple colour change, taking this technology closer to being a realistic biosensor.
authors.affiliation: Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
authors.forename: Lucienne
authors.initials: L
authors.lastname: Otten
authors.forename: Denise
authors.initials: D
authors.lastname: Vlachou
authors.forename: Sarah-Jane
authors.initials: SJ
authors.lastname: Richards
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Gibson
mesh_terms: D015374:Biosensing Techniques; D006046:Gold; D037102:Lectins / Q000737:chemistry*; D053768:Metal Nanoparticles; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D037102:Lectins; D011134:Polysaccharides; D006046:Gold