title: Optimizing Nanoplasmonic Biosensor Sensitivity with Orientated Single Domain Antibodies.
abstract: Localized surface plasmon resonance (LSPR) spectroscopy and imaging are emerging biosensor technologies which tout label-free biomolecule detection at the nanoscale and ease of integration with standard microscopy setups. The applicability of these techniques can be limited by the restrictions that surface-conjugated ligands must be both sufficiently small and orientated to meet analyte sensitivity requirements. We demonstrate that orientated single domain antibodies (sdAb) can optimize nanoplasmonic sensitivity by comparing three anti-ricin sdAb constructs to biotin-neutravidin, a model system for small and highly orientated ligand studies. LSPR imaging of electrostatically orientated sdAb exhibited a ricin sensitivity equivalent to that of the biotinylated LSPR biosensors for neutravidin. These results, combined with the facts that sdAb are highly stable and readily produced in bacteria and yeast, build a compelling case for the increased utilization of sdAbs in nanoplasmonic applications.
authors.affiliation: Bioelectronics and Sensing, Code 6363, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: Marc P
authors.initials: MP
authors.lastname: Raphael
authors.affiliation: Bioelectronics and Sensing, Code 6363, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Christodoulides
authors.affiliation: Bioelectronics and Sensing, Code 6363, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: Jeff M
authors.initials: JM
authors.lastname: Byers
authors.affiliation: Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: George P
authors.initials: GP
authors.lastname: Anderson
authors.affiliation: Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: Jinny L
authors.initials: JL
authors.lastname: Liu
authors.affiliation: Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: Kendrick B
authors.initials: KB
authors.lastname: Turner
authors.affiliation: Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: Ellen R
authors.initials: ER
authors.lastname: Goldman
authors.affiliation: Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Delehanty
keywords: Bio-threat; LSPR; Orientation; Ricin; SPR; Single domain antibodies