Prion diseases are a group of fatal transmissible neurological conditions caused by the change in conformation of intrinsic cellular prion protein (PrPC). We present a rapid assay using aptamers and resistive pulse sensing, RPS, to extract and quantify PrPC from complex sample matrices. We functionalise the surface of superparamagnetic beads, SPBs, with a DNA aptamer. First SPB's termed P-beads, are used to pre-concentrate the analyte from a large sample volume. The PrPC protein is then eluted from the P-beads before aptamer modified sensing beads, S-beads, are added. The velocity of the S-beads through the nanopore reveals the concentration of the PrPC protein. The process is done in under an hour and allows the detection of picomol's of protein.