Evaluation of Bio-Layer Interferometric Biosensors for Label-Free Rapid Detection of Norovirus Using Virus Like Particles

This study evaluated the label-free bio-layer interferometric (BLI) biosensor for the detection of norovirus (NoV) using two types of virus like particles (VLPs) that represent human NoV GI.1 and GII.4. To construct biosensors for NoV GI.1 and GII.4 detection, the commercial AMC sensors, on which anti-mouse Fc-specific antibodies were preimmobilized on the surfaces, were further bound with the capture antibodies mAb3901 and mAb NS14, respectively, by using the Blitz system. The kinetics of immobilization of capture antibodies on the AMC sensors demonstrated that mAb3901 and mAb NS14 reached saturated binding phase almost at the same time (~415 s). The optimal concentration of capture antibodies for immobilization was 15 μg/mL for both mAb3901 and mAb NS14. The AMC sensors loaded more mAb NS14 than mAb3901 at the same binding condition. The biosensors constructed by immobilization of the capture antibodies at their optimal concentration showed tight binding interactions with their respective GI.1 VLPs and GII.4 VLPs, with the affinity constant of 6.01 × 10-7 M and 2.01 × 10-7 M, respectively. For both biosensors, the VLPs binding rates were linearly increased with the increase of VLP concentrations. These biosensors were able to detect GI.1 or GII.4 VLPs at the concentration of 5 μg/mL in PBS, and showed intense and stable binding interactions at VLP concentration of 10 μg/mL and above. The mAb NS14-immoblized biosensors for GII.4 VLP detection were more sensitive than the mAb3901-immoblized biosensors for GI.1 VLP detection. This detection technique was label-free, easy, rapid (2 min), and accurate, requiring a very small sample volume (4 μL).