The influence of nanoparticles of various sizes and surface functionalities on the self-assembling fibrillogenesis of beta-amyloid (1-40) peptide was investigated. Functionalized nanoparticles including quantum dots and gold nanoparticles were co-incubated with monomeric Aβ(1-40) peptides under seed-mediated growth method to study their influences on the elongation phase of the fibrillogenesis. It is observed that charge-to-surface area ratio of the nanoparticles and the functional moiety and electrostatic charges of the conjugated ligands on the particle surfaces took crucial regulatory role in the Aβ(1-40) fibrillogenesis.