demonstrated that, when measuring the intensity of different AuNP sizes, the LOD for visual detection of 115 nm AuNPs was roughly 467-fold lower than that of smaller 16 nm particles, when spotted directly onto membrane. Nanoparticle size also significantly influences a particle's binding affinity towards its target by virtue of the available surface area for receptor functionalisation. For antibody-nanoparticle conjugates, this enables greater numbers of antibodies per particle and increased particle valency when binding target.