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A Comparison of Ion Channel Current Blockades Caused by Individual Poly(ethylene glycol) Molecules and Polyoxometalate Nanoclusters



Haiyan Wang, John J. Kasianowicz, Joseph W. Robertson, Dianne L. Poster, Jessica Ettedgui


Proteinaceous nanometer-scale pores have been used to detect and physically characterize many different types of molecules at the single molecule limit. The method is based on the ability to measure the transient reduction in the ionic channel conductance caused by molecules partitioning into the pore. The distribution of blockade depth amplitudes and residence times of the molecules in the pore are used to physically and chemically characterize the molecules. We compare here the current blockades caused by flexible, linear polymers of ethylene glycol (PEGs) and structurally well-defined metallic nanoparticles. Surprisingly, the variance in the ionic current blockade values for the metallic nanoparticles is much greater than that for the PEGs. We suggest a possible rationale for this finding.
European Physical Journal E


ion channels, PEG, POMs, proteins, nanopores
Created June 28, 2019, Updated January 27, 2020