title: Single Molecule Discrimination of Heteropolytungstates and Their Isomers in Solution with a Nanometer-Scale Pore.
abstract: We report a new method to identify metallic nanoclusters (polyoxometalate structures) in solution at the single molecule limit using a nanometer-scale pore. The technique allows the measurement of polyoxometalates with over 2 orders of magnitude lower analyte concentration than conventional analytical chemistry tools. Furthermore, pH-dependent structural changes in phosphotungstic acid are measured with protein nanopores and validated with NMR. We further demonstrate that the method can also discriminate [PW9O34](9-) structural isomers. The results suggest this technique can serve as a complementary approach to traditional methods.
authors.affiliation: Engineering Physics Division, Physical Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.|Department of Chemical Engineering, Columbia University , New York, New York 10027-6623, United States.
authors.forename: Jessica
authors.initials: J
authors.lastname: Ettedgui
authors.affiliation: Engineering Physics Division, Physical Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: Kasianowicz
authors.affiliation: Engineering Physics Division, Physical Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Arvind
authors.initials: A
authors.lastname: Balijepalli
mesh_terms: D055664:Electrochemical Techniques; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D008956:Models, Chemical; D058608:Nanopores / Q000648:ultrastructure*; D010772:Phosphotungstic Acid / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry / Q000648:ultrastructure; D012996:Solutions; D055672:Static Electricity
chemical_list: D011506:Proteins; D012996:Solutions; D010772:Phosphotungstic Acid