Natwi - Kasianowicz & Schilling

“Electronically detecting and physically characterizing single molecules”

Biological nanometer-scale protein pores are the basis of many critical functions, including nerve and muscle activity and the transport of macromolecules across cell membranes.  We have been adapting them for the detection, characterization, and identification of ions and macromolecules in aqueous solution.  In the absence of analyte, an applied voltage drives ions through the nanopore.  When a single analyte of interest enters the pore, its physical and chemical properties control both the degree by which it reduces the ionic current and its residence time there.  The method has been used to sequence DNA, discriminate between polymers based on their size, and identify subtly different species of metallo-nanoparticles.  With the ultimate goal of providing low-cost measurements for health care applications, we are currently trying to modify the technique to identify proteins.