title: Dynamic control of nanoprecipitation in a nanopipette.
abstract: Studying the earliest stages of precipitation at the nanoscale is technically challenging but quite valuable as such phenomena reflect important processes such as crystallization and biomineralization. Using a quartz nanopipette as a nanoreactor, we induced precipitation of an insoluble salt to generate oscillating current blockades. The reversible process can be used to measure both kinetics of precipitation and relative size of the resulting nanoparticles. Counter ions for the highly water-insoluble salt zinc phosphate were separated by the pore of a nanopipette and a potential applied to cause ion migration to the interface. By analyzing the kinetics of pore blockage, two distinct mechanisms were identified: a slower process due to precipitation from solution, and a faster process attributed to voltage-driven migration of a trapped precipitate. We discuss the potential of these techniques in studying precipitation dynamics, trapping particles within a nanoreactor, and electrical sensors based on nanoprecipitation.
authors.affiliation: Department of Biomolecular Engineering, University of California Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA.
authors.forename: Boaz
authors.initials: B
authors.lastname: Vilozny
authors.forename: Paolo
authors.initials: P
authors.lastname: Actis
authors.forename: R Adam
authors.initials: RA
authors.lastname: Seger
authors.forename: Nader
authors.initials: N
authors.lastname: Pourmand
mesh_terms: D007700:Kinetics; D036103:Nanotechnology; D010710:Phosphates / Q000737:chemistry; D012995:Solubility; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D010710:Phosphates; D017967:Zinc Compounds; C043952:zinc phosphate