A similar sandwich immunosensor was fabricated by using Fe3O4NPs and a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) conductive composite (Fe3O4/PEDOT:PSS) for the detection of prostate-specific antigen (PSA, linked to prostate cancer) [62]. The gene discussed is KLK3; the disease is Familial prostate cancer.