Fig. 1: Different generations of nanobodies were used in this work and integrated into the electrochemical sensing device.
From: SARS-CoV-2 detection using a nanobody-functionalized voltammetric device
Surface and ribbon views of the VHHs (the three CDRs are colored red, green, blue, respectively): A VHH-72 can bind the sensor in different orientations. B VHH-72-C13 is oriented on the sensor by the Cys link (yellow). The direct linkage to the gold electrode is shown rather than the thiol-PEG-MAL linker, considered more meaningful. C VHH11-D4-C13 is oriented on the sensor surface by the Cys link (yellow). D Ribbon views of the two VHHs bound to the Spike RBD (rainbow colored, white surface). Note the large distance between the two epitopes. VHHs affinity constants determined by BLI: VHH-72 (KD = 36.6 nM), VHH-72-13C (KD = 12.1 nM), VHH-H11D4-13C (KD = 5 nM).
