A multiplexing electrochemical immunosensor was developed for the detection of prostate specific antigen (PSA) and interleukin 8 (IL-8) cancer related proteins by using a disposable screen-printed carbon electrode (SPCE) array with 16 elements as the detection platform, and a multi-labeled nanoprobe prepared by loading HRP and goat anti-rabbit IgG onto multiwalled carbon nanotubes (MWCNTs). Here, KLK3 is linked to cancer.