An amyloidogenic peptide biospecific agent comprises a nanoparticle which is visible under near infrared (NIR) and/or using Magnetic Resonance Imaging (MRI) and/or Computed Tomography (CT). The biospecific agent further comprises at least one antibody or antigen binding fragment thereof, which is immunospecific for a transferrin receptor and an amyloidogenic peptide. FIGURE: 1