Fig. 1.

a SPR response to the conjugation of C8-zip sdAbs for a range of ligand concentrations followed by the introduction of 100 nM ricin in (b). The control study in b consisted of a 100-nM ricin solution incubated with 5 μM of C8 for 45 min to block the binding sites. It was then introduced over a 4.0-μg/mL C8 functionalized surface. The vertical dashed line separates the association phase (left) in which the ligand or analyte solution is flowing over the surface from the dissociation phase (right) in which buffer flows over the surface