Next, we combined 100 µL of 0.1% (1X PBS) containing 0.01% Tween-20 with the nanoparticles, applied the mixture to the sample pad of the LFIA strip, and allowed it to run for 10 minutes. Then, 200 µL of running buffer (0.01% Tween-20 in 0.1% 1 X PBS) was added to facilitate nanoparticle migration from the sample pad to the wicking pad over 10-15 minutes. For GNSP, we introduced 100 µL of the RVFV nucleoprotein solution onto the sample pad and conducted the assay. For blood serum samples, RVFV protein was spiked into 20 mL of blood serum. After magnetic concentration of the nanoparticles for 5 minutes, we mixed the nanoparticles with 100 µL of 0.1 % (1X PBS) containing 0.01% Tween-20 and applied onto the sample pad of the LFIA strip and run for 10 minutes. Then, 200 µL of running buffer (0.01% Tween-20 in 0.1% 1 X PBS) was added to facilitate nanoparticle migration from the sample pad to the wicking pad over 10-15 minutes.