As previously discussed, the anisotropic sharp-spiked morphology enhances the optical brightness of the nanoparticle system, with mpGNS-3 displaying the highest color intensity. We further evaluated the LFIA performance of the nanoparticle systems at the same concentration and conducted the LFIA assay at an RVFV nucleoprotein concentration of 2.5 ng/mL. Figure (bottom) presents photographs of LFIA strips with different nanoparticle systems. Figure displays the gray value profile of the nanoparticle systems, while Figure illustrates the gray value intensity of the test lines. The results show that the gray value intensity of mpGNS-3 was nearly twice as high as that of Fe3O4@PDA nanoparticles. This finding confirms that mpGNS-3, being a plasmonic-rich nanoparticle system, enhances optical brightness and significantly increases LFIA intensity. We evaluated the antibody coupling efficiency of the nanoparticles by measuring the antibody concentration using absorbance analysis of the detection antibodies bound to mpGNS. As shown in Figure , mpGNS-3 exhibited a higher coupling efficiency (70 %) compared to Fe3O4@PDA (35 %), demonstrating its effectiveness as a target antibody-labeling LFIA platform. As expected, the multiple sharp branches of mpGNS-3 increase the surface area of the nanoparticle system, thereby enhancing antibody conjugation efficiency relative to other mpGNS variants and Fe3O4@PDA. We compared the gray value intensity of mpGNS-3 with traditional GNP and Fe3O4@PDA at an RVFV nucleoprotein concentration of 200 ng/mL across different detection antibody concentrations ranging from 5 µg/mL to 750 µg/mL (Figure ). The LFIA assay was performed with magnetic concentration for mpGNS-3 and Fe3O4@PDA, while GNP underwent a traditional colorimetric LFIA assay without magnetic concentration, as it lacks magnetic properties. The results indicate that gray value intensity increased with higher detection antibody concentrations, reaching a maximum at approximately 750 µg/mL. Notably, mpGNS-3 exhibited the highest gray value intensity compared to GNP and Fe3O4@PDA. As expected, mpGNS-3 leverages both strong plasmonic effects, which enhance the color intensity of the LFIA test line, and magnetic concentration, which increases analyte accumulation, thereby achieving greater LFIA sensitivity than Fe3O4@PDA and traditional GNP.