Fluorescence Microscopy Assay. To verify the specific adsorption of fluorescently labeled CRP on anti-CRP mAb-functionalized GFETs, fluorescence images were taken after the electrical measurements using a fluorescence microscope (ECLIPSE LV100N POL, Nikon) equipped with a 50× objective lens (TU Plan Fluor, NA 0.8, Nikon). Images were captured at an exposure time of 1 s.