A novel strategy for nanopore-based selective detection of single carcinoembryonic antigen (CEA) molecules.

Nanopores have become one of important tools for single molecule sensing, but the challenge for selective detection of specific biomolecules is still existed. In this contribution, we develop a new technique for sensing carcinoembryonic antigen (CEA), one of the important cancer biomarkers, using solid-state nanopore as a tool. The method is based on the specific affinity between aptamer (Apt) modified magnetic Fe3O4-Au nanoparticles (MNPs) and CEA, and the formed CEA-Apt-MNPs and remained Apt-MNPs can transport the nanopore by applied a positive potential after magnetic separation. Due to the obvious particle size difference between CEA-Apt-MNPs and Apt-MPs, their corresponding blockage signals could be distinguished completely by the degree of the current decline. Moreover, the frequency of the blockage signals for CEA-Apt-MNPs is proportional to the concentration of CEA within certain limits, indicating that our designed nanopore sensing strategy can quantitatively detect CEA in complex samples. This w...